v3.26.1
Risk/Return Detail Data - FidelitySustainableTargetDateFunds-ComboRetailPro - USD ($)
 12 Months Ended 24 Months Ended 36 Months Ended
May 30, 2026
May 30, 2026
Dec. 31, 2025
Dec. 31, 2024
May 30, 2026
May 30, 2026
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date Retirement Fund | Fidelity Sustainable Target Date Retirement Fund - Class K            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [1] 0.31%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [1] 0.31%          
Expense Example, with Redemption, 1 Year $ 32          
Expense Example, with Redemption, 3 Years 100          
Expense Example, with Redemption, 5 Years 174          
Expense Example, with Redemption, 10 Years $ 393          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K        
Average Annual Return, Percent   9.71%       6.66% [2]
Annual Return [Percent]     9.71% 4.12%    
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date Retirement Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date Retirement Fund /K            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date Retirement Fund seeks high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 36 % of the average value of its portfolio.          
Portfolio Turnover, Rate 36.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a stable neutral asset allocation strategy. A revised neutral asset allocation strategy (approximately 18% in U.S. equity funds, 12% in international equity funds, 33% in U.S. investment grade bond funds, 5% in international bond funds, 2% in long-term treasury bond funds, 24% in short-term inflation protected bond funds, and 7% in short-term funds; allocations do not add to 100% due to rounding) is expected to take effect by the end of the first quarter of 2027. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.07%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Sep. 30, 2024          
Highest Quarterly Return 4.58%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.37%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date Retirement Fund | IXUFW            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date Retirement Composite Index℠        
Average Annual Return, Percent   9.31%       6.91%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date Retirement Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2010 Fund | Fidelity Sustainable Target Date 2010 Fund - Class K            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [3] 0.31%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [3] 0.31%          
Expense Example, with Redemption, 1 Year $ 32          
Expense Example, with Redemption, 3 Years 100          
Expense Example, with Redemption, 5 Years 174          
Expense Example, with Redemption, 10 Years $ 393          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K        
Average Annual Return, Percent   10.67%       7.68% [4]
Annual Return [Percent]     10.67% 4.95%    
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2010 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2010 Fund /K            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2010 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 30 % of the average value of its portfolio.          
Portfolio Turnover, Rate 30.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2010. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who retired in or within a few years of 2010 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.18%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Sep. 30, 2024          
Highest Quarterly Return 4.90%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.55%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2010 Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2010 Fund | IXUFX            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2010 Composite Index℠        
Average Annual Return, Percent   10.22%       7.87%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2015 Fund | Fidelity Sustainable Target Date 2015 Fund - Class K            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [5] 0.32%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [5] 0.32%          
Expense Example, with Redemption, 1 Year $ 33          
Expense Example, with Redemption, 3 Years 103          
Expense Example, with Redemption, 5 Years 180          
Expense Example, with Redemption, 10 Years $ 406          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K        
Average Annual Return, Percent   12.25%       8.93% [6]
Annual Return [Percent]     12.25% 5.85%    
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2015 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2015 Fund /K            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2015 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2015. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who retired in or within a few years of 2015 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.35%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Sep. 30, 2024          
Highest Quarterly Return 5.19%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.78%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2015 Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2015 Fund | IXUFY            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2015 Composite Index℠        
Average Annual Return, Percent   11.75%       9.11%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2020 Fund | Fidelity Sustainable Target Date 2020 Fund - Class K            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [7] 0.33%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [7] 0.33%          
Expense Example, with Redemption, 1 Year $ 34          
Expense Example, with Redemption, 3 Years 106          
Expense Example, with Redemption, 5 Years 185          
Expense Example, with Redemption, 10 Years $ 418          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K        
Average Annual Return, Percent   13.83%       10.21% [8]
Annual Return [Percent]     13.83% 6.67%    
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2020 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2020 Fund /K            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2020 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 31 % of the average value of its portfolio.          
Portfolio Turnover, Rate 31.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2020. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who retired in or within a few years of 2020 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.58%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 5.92%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (3.06%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2020 Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2020 Fund | IXUFZ            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2020 Composite Index℠        
Average Annual Return, Percent   13.30%       10.36%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2025 Fund | Fidelity Sustainable Target Date 2025 Fund - Class K            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [9] 0.34%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [9] 0.34%          
Expense Example, with Redemption, 1 Year $ 35          
Expense Example, with Redemption, 3 Years 109          
Expense Example, with Redemption, 5 Years 191          
Expense Example, with Redemption, 10 Years $ 431          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K        
Average Annual Return, Percent   15.24%       11.32% [10]
Annual Return [Percent]     15.24% 7.47%    
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2025 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2025 Fund /K            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2025 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 29 % of the average value of its portfolio.          
Portfolio Turnover, Rate 29.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2025. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2025 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.80%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 6.68%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (3.20%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2025 Fund | IXUG2            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2025 Composite Index℠        
Average Annual Return, Percent   14.75%       11.51%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2025 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2030 Fund | Fidelity Sustainable Target Date 2030 Fund - Class K            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [11] 0.35%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [11] 0.35%          
Expense Example, with Redemption, 1 Year $ 36          
Expense Example, with Redemption, 3 Years 113          
Expense Example, with Redemption, 5 Years 197          
Expense Example, with Redemption, 10 Years $ 443          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K        
Average Annual Return, Percent   16.15%       12.43% [12]
Annual Return [Percent]     16.15% 8.52%    
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2030 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2030 Fund /K            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2030 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 43 % of the average value of its portfolio.          
Portfolio Turnover, Rate 43.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2030. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2030 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.85%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 7.42%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (3.05%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2030 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2030 Fund | IXUG3            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2030 Composite Index℠        
Average Annual Return, Percent   15.73%       12.60%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2035 Fund | Fidelity Sustainable Target Date 2035 Fund - Class K            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [13] 0.37%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [13] 0.37%          
Expense Example, with Redemption, 1 Year $ 38          
Expense Example, with Redemption, 3 Years 119          
Expense Example, with Redemption, 5 Years 208          
Expense Example, with Redemption, 10 Years $ 468          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K        
Average Annual Return, Percent   17.48%       14.18% [14]
Annual Return [Percent]     17.48% 10.10%    
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2035 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2035 Fund /K            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2035 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 26 % of the average value of its portfolio.          
Portfolio Turnover, Rate 26.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2035. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2035 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.97%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 8.50%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.85%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2035 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2035 Fund | IXUG5            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2035 Composite Index℠        
Average Annual Return, Percent   17.08%       14.32%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2040 Fund | Fidelity Sustainable Target Date 2040 Fund - Class K            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [15] 0.38%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [15] 0.38%          
Expense Example, with Redemption, 1 Year $ 39          
Expense Example, with Redemption, 3 Years 122          
Expense Example, with Redemption, 5 Years 213          
Expense Example, with Redemption, 10 Years $ 480          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K        
Average Annual Return, Percent   19.93%       16.54% [16]
Annual Return [Percent]     19.93% 12.26%    
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2040 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2040 Fund /K            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2040 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2040. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2040 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.25%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.06%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.60%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2040 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2040 Fund | IXUG8            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2040 Composite Index℠        
Average Annual Return, Percent   19.54%       16.61%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2045 Fund | Fidelity Sustainable Target Date 2045 Fund - Class K            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [17] 0.39%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [17] 0.39%          
Expense Example, with Redemption, 1 Year $ 40          
Expense Example, with Redemption, 3 Years 125          
Expense Example, with Redemption, 5 Years 219          
Expense Example, with Redemption, 10 Years $ 493          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K        
Average Annual Return, Percent   21.19%       17.51% [18]
Annual Return [Percent]     21.19% 13.16%    
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2045 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2045 Fund /K            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2045 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2045. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2045 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.43%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.90%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.49%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2045 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2045 Fund | IXUG9            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2045 Composite Index℠        
Average Annual Return, Percent   20.97%       17.60%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2050 Fund | Fidelity Sustainable Target Date 2050 Fund - Class K            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [19] 0.39%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [19] 0.39%          
Expense Example, with Redemption, 1 Year $ 40          
Expense Example, with Redemption, 3 Years 125          
Expense Example, with Redemption, 5 Years 219          
Expense Example, with Redemption, 10 Years $ 493          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K        
Average Annual Return, Percent   21.32%       17.53% [20]
Annual Return [Percent]     21.32% 13.10%    
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2050 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2050 Fund /K            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2050 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2050. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2050 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.49%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.92%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.54%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2050 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2050 Fund | IXUGA            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2050 Composite Index℠        
Average Annual Return, Percent   20.98%       17.61%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2055 Fund | Fidelity Sustainable Target Date 2055 Fund - Class K            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [21] 0.39%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [21] 0.39%          
Expense Example, with Redemption, 1 Year $ 40          
Expense Example, with Redemption, 3 Years 125          
Expense Example, with Redemption, 5 Years 219          
Expense Example, with Redemption, 10 Years $ 493          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K        
Average Annual Return, Percent   21.32%       17.53% [22]
Annual Return [Percent]     21.32% 13.03%    
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2055 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2055 Fund /K            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2055 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 20 % of the average value of its portfolio.          
Portfolio Turnover, Rate 20.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2055. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2055 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.49%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.94%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.52%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2055 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2055 Fund | IXUGF            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2055 Composite Index℠        
Average Annual Return, Percent   21.00%       17.61%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2060 Fund | Fidelity Sustainable Target Date 2060 Fund - Class K            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [23] 0.39%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [23] 0.39%          
Expense Example, with Redemption, 1 Year $ 40          
Expense Example, with Redemption, 3 Years 125          
Expense Example, with Redemption, 5 Years 219          
Expense Example, with Redemption, 10 Years $ 493          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K        
Average Annual Return, Percent   21.34%       17.54% [24]
Annual Return [Percent]     21.34% 13.08%    
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2060 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2060 Fund /K            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2060 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 26 % of the average value of its portfolio.          
Portfolio Turnover, Rate 26.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2060. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2060 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.50%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.91%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.49%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2060 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2060 Fund | IXUGG            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2060 Composite Index℠        
Average Annual Return, Percent   21.00%       17.61%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2065 Fund | Fidelity Sustainable Target Date 2065 Fund - Class K            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [25] 0.39%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [25] 0.39%          
Expense Example, with Redemption, 1 Year $ 40          
Expense Example, with Redemption, 3 Years 125          
Expense Example, with Redemption, 5 Years 219          
Expense Example, with Redemption, 10 Years $ 493          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K        
Average Annual Return, Percent   21.23%       17.52% [26]
Annual Return [Percent]     21.23% 13.05%    
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2065 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2065 Fund /K            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2065 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 20 % of the average value of its portfolio.          
Portfolio Turnover, Rate 20.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2065. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2065 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.43%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.90%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.48%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2065 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2065 Fund | IXUGH            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2065 Composite Index℠        
Average Annual Return, Percent   21.00%       17.61%
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2070 Fund | Fidelity Sustainable Target Date 2070 Fund - Class K            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [27] 0.39%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [27] 0.39%          
Expense Example, with Redemption, 1 Year $ 40          
Expense Example, with Redemption, 3 Years 125          
Expense Example, with Redemption, 5 Years 219          
Expense Example, with Redemption, 10 Years $ 493          
Annual Return, Inception Date Jun. 28, 2024          
Average Annual Return, Label [Optional Text]   Class K        
Average Annual Return, Percent   21.31%     16.33% [28]  
Annual Return [Percent]     21.31%      
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2070 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2070 Fund /K            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2070 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 19 % of the average value of its portfolio.          
Portfolio Turnover, Rate 19.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2070. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2070 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the performance of the fund's shares over the past year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the performance of the fund's shares over the past year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.48%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.88%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Mar. 31, 2025          
Lowest Quarterly Return (0.59%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2070 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%     17.78%  
FidelitySustainableTargetDateFunds-ComboClassKPro | Fidelity Sustainable Target Date 2070 Fund | IXTP0            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2070 Composite Index℠        
Average Annual Return, Percent   21.00%     17.21%  
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date Retirement Fund | Fidelity Sustainable Target Date Retirement Fund            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [29] 0.41%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [29] 0.41%          
Expense Example, with Redemption, 1 Year $ 42          
Expense Example, with Redemption, 3 Years 132          
Expense Example, with Redemption, 5 Years 230          
Expense Example, with Redemption, 10 Years $ 518          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   9.61%       6.57% [30]
Annual Return [Percent]     9.61% 4.03%    
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date Retirement Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date Retirement Fund /Fidelity® Sustainable Target Date Retirement Fund          
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date Retirement Fund seeks high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 36 % of the average value of its portfolio.          
Portfolio Turnover, Rate 36.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a stable neutral asset allocation strategy. A revised neutral asset allocation strategy (approximately 18% in U.S. equity funds, 12% in international equity funds, 33% in U.S. investment grade bond funds, 5% in international bond funds, 2% in long-term treasury bond funds, 24% in short-term inflation protected bond funds, and 7% in short-term funds; allocations do not add to 100% due to rounding) is expected to take effect by the end of the first quarter of 2027. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.17%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Sep. 30, 2024          
Highest Quarterly Return 4.56%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.41%)          
Performance Table Heading Average Annual Returns          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date Retirement Fund | After Taxes on Distributions | Fidelity Sustainable Target Date Retirement Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   8.14%       5.11% [30]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date Retirement Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Target Date Retirement Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   5.76%       4.44% [30]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date Retirement Fund | IXUFW            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date Retirement Composite Index℠        
Average Annual Return, Percent   9.31%       6.91%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date Retirement Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2010 Fund | Fidelity Sustainable Target Date 2010 Fund            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [31] 0.41%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [31] 0.41%          
Expense Example, with Redemption, 1 Year $ 42          
Expense Example, with Redemption, 3 Years 132          
Expense Example, with Redemption, 5 Years 230          
Expense Example, with Redemption, 10 Years $ 518          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   10.58%       7.55% [32]
Annual Return [Percent]     10.58% 4.77%    
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2010 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2010 Fund /Fidelity® Sustainable Target Date 2010 Fund          
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2010 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 30 % of the average value of its portfolio.          
Portfolio Turnover, Rate 30.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2010. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who retired in or within a few years of 2010 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.18%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Sep. 30, 2024          
Highest Quarterly Return 4.80%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.61%)          
Performance Table Heading Average Annual Returns          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2010 Fund | After Taxes on Distributions | Fidelity Sustainable Target Date 2010 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   9.14%       6.13% [32]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2010 Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Target Date 2010 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   6.42%       5.25% [32]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2010 Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2010 Fund | IXUFX            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2010 Composite Index℠        
Average Annual Return, Percent   10.22%       7.87%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2015 Fund | Fidelity Sustainable Target Date 2015 Fund            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [33] 0.42%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [33] 0.42%          
Expense Example, with Redemption, 1 Year $ 43          
Expense Example, with Redemption, 3 Years 135          
Expense Example, with Redemption, 5 Years 235          
Expense Example, with Redemption, 10 Years $ 530          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   12.14%       8.84% [34]
Annual Return [Percent]     12.14% 5.75%    
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2015 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2015 Fund /Fidelity® Sustainable Target Date 2015 Fund          
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2015 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2015. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who retired in or within a few years of 2015 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.44%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Sep. 30, 2024          
Highest Quarterly Return 5.19%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.85%)          
Performance Table Heading Average Annual Returns          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2015 Fund | After Taxes on Distributions | Fidelity Sustainable Target Date 2015 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   10.87%       7.57% [34]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2015 Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Target Date 2015 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   7.31%       6.33% [34]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2015 Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2015 Fund | IXUFY            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2015 Composite Index℠        
Average Annual Return, Percent   11.75%       9.11%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2020 Fund | Fidelity Sustainable Target Date 2020 Fund            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [35] 0.43%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [35] 0.43%          
Expense Example, with Redemption, 1 Year $ 44          
Expense Example, with Redemption, 3 Years 138          
Expense Example, with Redemption, 5 Years 241          
Expense Example, with Redemption, 10 Years $ 542          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   13.66%       10.08% [36]
Annual Return [Percent]     13.66% 6.65%    
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2020 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2020 Fund /Fidelity® Sustainable Target Date 2020 Fund          
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2020 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 31 % of the average value of its portfolio.          
Portfolio Turnover, Rate 31.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2020. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who retired in or within a few years of 2020 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.59%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 5.80%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (3.07%)          
Performance Table Heading Average Annual Returns          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2020 Fund | After Taxes on Distributions | Fidelity Sustainable Target Date 2020 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   12.53%       8.98% [36]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2020 Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Target Date 2020 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   8.27%       7.40% [36]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2020 Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2020 Fund | IXUFZ            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2020 Composite Index℠        
Average Annual Return, Percent   13.30%       10.36%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2025 Fund | Fidelity Sustainable Target Date 2025 Fund            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [37] 0.44%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [37] 0.44%          
Expense Example, with Redemption, 1 Year $ 45          
Expense Example, with Redemption, 3 Years 141          
Expense Example, with Redemption, 5 Years 246          
Expense Example, with Redemption, 10 Years $ 555          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   15.00%       11.18% [38]
Annual Return [Percent]     15.00% 7.32%    
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2025 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2025 Fund /Fidelity® Sustainable Target Date 2025 Fund          
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2025 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 29 % of the average value of its portfolio.          
Portfolio Turnover, Rate 29.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2025. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2025 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.72%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 6.59%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (3.24%)          
Performance Table Heading Average Annual Returns          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2025 Fund | After Taxes on Distributions | Fidelity Sustainable Target Date 2025 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   14.16%       10.29% [38]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2025 Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Target Date 2025 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   9.02%       8.36% [38]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2025 Fund | IXUG2            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2025 Composite Index℠        
Average Annual Return, Percent   14.75%       11.51%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2025 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2030 Fund | Fidelity Sustainable Target Date 2030 Fund            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [39] 0.45%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [39] 0.45%          
Expense Example, with Redemption, 1 Year $ 46          
Expense Example, with Redemption, 3 Years 144          
Expense Example, with Redemption, 5 Years 252          
Expense Example, with Redemption, 10 Years $ 567          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   16.00%       12.29% [40]
Annual Return [Percent]     16.00% 8.36%    
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2030 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2030 Fund /Fidelity® Sustainable Target Date 2030 Fund          
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2030 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 43 % of the average value of its portfolio.          
Portfolio Turnover, Rate 43.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2030. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2030 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.86%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 7.42%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (3.04%)          
Performance Table Heading Average Annual Returns          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2030 Fund | After Taxes on Distributions | Fidelity Sustainable Target Date 2030 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   15.16%       11.48% [40]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2030 Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Target Date 2030 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   9.66%       9.29% [40]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2030 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2030 Fund | IXUG3            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2030 Composite Index℠        
Average Annual Return, Percent   15.73%       12.60%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2035 Fund | Fidelity Sustainable Target Date 2035 Fund            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [41] 0.47%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [41] 0.47%          
Expense Example, with Redemption, 1 Year $ 48          
Expense Example, with Redemption, 3 Years 151          
Expense Example, with Redemption, 5 Years 263          
Expense Example, with Redemption, 10 Years $ 591          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   17.35%       14.07% [42]
Annual Return [Percent]     17.35% 10.03%    
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2035 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2035 Fund /Fidelity® Sustainable Target Date 2035 Fund          
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2035 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 26 % of the average value of its portfolio.          
Portfolio Turnover, Rate 26.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2035. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2035 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.97%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 8.41%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.86%)          
Performance Table Heading Average Annual Returns          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2035 Fund | After Taxes on Distributions | Fidelity Sustainable Target Date 2035 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   16.64%       13.36% [42]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2035 Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Target Date 2035 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   10.48%       10.76% [42]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2035 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2035 Fund | IXUG5            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2035 Composite Index℠        
Average Annual Return, Percent   17.08%       14.32%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2040 Fund | Fidelity Sustainable Target Date 2040 Fund            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [43] 0.48%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [43] 0.48%          
Expense Example, with Redemption, 1 Year $ 49          
Expense Example, with Redemption, 3 Years 154          
Expense Example, with Redemption, 5 Years 269          
Expense Example, with Redemption, 10 Years $ 604          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   19.91%       16.43% [44]
Annual Return [Percent]     19.91% 12.12%    
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2040 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2040 Fund /Fidelity® Sustainable Target Date 2040 Fund          
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2040 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2040. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2040 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.26%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.01%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.68%)          
Performance Table Heading Average Annual Returns          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2040 Fund | After Taxes on Distributions | Fidelity Sustainable Target Date 2040 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   19.39%       15.91% [44]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2040 Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Target Date 2040 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   12.05%       12.75% [44]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2040 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2040 Fund | IXUG8            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2040 Composite Index℠        
Average Annual Return, Percent   19.54%       16.61%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2045 Fund | Fidelity Sustainable Target Date 2045 Fund            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [45] 0.49%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [45] 0.49%          
Expense Example, with Redemption, 1 Year $ 50          
Expense Example, with Redemption, 3 Years 157          
Expense Example, with Redemption, 5 Years 274          
Expense Example, with Redemption, 10 Years $ 616          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.13%       17.38% [46]
Annual Return [Percent]     21.13% 12.95%    
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2045 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2045 Fund /Fidelity® Sustainable Target Date 2045 Fund          
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2045 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2045. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2045 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.43%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.85%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.54%)          
Performance Table Heading Average Annual Returns          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2045 Fund | After Taxes on Distributions | Fidelity Sustainable Target Date 2045 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   20.69%       16.91% [46]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2045 Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Target Date 2045 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   12.81%       13.55% [46]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2045 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2045 Fund | IXUG9            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2045 Composite Index℠        
Average Annual Return, Percent   20.97%       17.60%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2050 Fund | Fidelity Sustainable Target Date 2050 Fund            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [47] 0.49%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [47] 0.49%          
Expense Example, with Redemption, 1 Year $ 50          
Expense Example, with Redemption, 3 Years 157          
Expense Example, with Redemption, 5 Years 274          
Expense Example, with Redemption, 10 Years $ 616          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.20%       17.40% [48]
Annual Return [Percent]     21.20% 12.96%    
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2050 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2050 Fund /Fidelity® Sustainable Target Date 2050 Fund          
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2050 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2050. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2050 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.50%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.87%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.52%)          
Performance Table Heading Average Annual Returns          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2050 Fund | After Taxes on Distributions | Fidelity Sustainable Target Date 2050 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   20.75%       16.95% [48]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2050 Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Target Date 2050 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   12.84%       13.58% [48]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2050 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2050 Fund | IXUGA            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2050 Composite Index℠        
Average Annual Return, Percent   20.98%       17.61%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2055 Fund | Fidelity Sustainable Target Date 2055 Fund            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [49] 0.49%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [49] 0.49%          
Expense Example, with Redemption, 1 Year $ 50          
Expense Example, with Redemption, 3 Years 157          
Expense Example, with Redemption, 5 Years 274          
Expense Example, with Redemption, 10 Years $ 616          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.17%       17.43% [50]
Annual Return [Percent]     21.17% 12.97%    
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2055 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2055 Fund /Fidelity® Sustainable Target Date 2055 Fund          
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2055 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 20 % of the average value of its portfolio.          
Portfolio Turnover, Rate 20.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2055. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2055 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.50%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.89%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.53%)          
Performance Table Heading Average Annual Returns          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2055 Fund | After Taxes on Distributions | Fidelity Sustainable Target Date 2055 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   20.73%       16.99% [50]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2055 Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Target Date 2055 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   12.83%       13.61% [50]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2055 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2055 Fund | IXUGF            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2055 Composite Index℠        
Average Annual Return, Percent   21.00%       17.61%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2060 Fund | Fidelity Sustainable Target Date 2060 Fund            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [51] 0.49%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [51] 0.49%          
Expense Example, with Redemption, 1 Year $ 50          
Expense Example, with Redemption, 3 Years 157          
Expense Example, with Redemption, 5 Years 274          
Expense Example, with Redemption, 10 Years $ 616          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.18%       17.43% [52]
Annual Return [Percent]     21.18% 13.04%    
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2060 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2060 Fund /Fidelity® Sustainable Target Date 2060 Fund          
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2060 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 26 % of the average value of its portfolio.          
Portfolio Turnover, Rate 26.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2060. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2060 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.50%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.86%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.49%)          
Performance Table Heading Average Annual Returns          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2060 Fund | After Taxes on Distributions | Fidelity Sustainable Target Date 2060 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   20.74%       16.97% [52]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2060 Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Target Date 2060 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   12.83%       13.60% [52]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2060 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2060 Fund | IXUGG            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2060 Composite Index℠        
Average Annual Return, Percent   21.00%       17.61%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2065 Fund | Fidelity Sustainable Target Date 2065 Fund            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [53] 0.49%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [53] 0.49%          
Expense Example, with Redemption, 1 Year $ 50          
Expense Example, with Redemption, 3 Years 157          
Expense Example, with Redemption, 5 Years 274          
Expense Example, with Redemption, 10 Years $ 616          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.17%       17.41% [54]
Annual Return [Percent]     21.17% 13.00%    
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2065 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2065 Fund /Fidelity® Sustainable Target Date 2065 Fund          
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2065 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 20 % of the average value of its portfolio.          
Portfolio Turnover, Rate 20.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2065. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2065 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.50%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.92%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.57%)          
Performance Table Heading Average Annual Returns          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2065 Fund | After Taxes on Distributions | Fidelity Sustainable Target Date 2065 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   20.74%       16.96% [54]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2065 Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Target Date 2065 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   12.83%       13.58% [54]
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2065 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2065 Fund | IXUGH            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2065 Composite Index℠        
Average Annual Return, Percent   21.00%       17.61%
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2070 Fund | Fidelity Sustainable Target Date 2070 Fund            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [55] 0.49%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [55] 0.49%          
Expense Example, with Redemption, 1 Year $ 50          
Expense Example, with Redemption, 3 Years 157          
Expense Example, with Redemption, 5 Years 274          
Expense Example, with Redemption, 10 Years $ 616          
Annual Return, Inception Date Jun. 28, 2024          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.18%     16.23% [56]  
Annual Return [Percent]     21.18%      
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2070 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2070 Fund /Fidelity® Sustainable Target Date 2070 Fund          
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2070 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 19 % of the average value of its portfolio.          
Portfolio Turnover, Rate 19.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2070. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2070 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the performance of the fund's shares over the past year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit www.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the performance of the fund's shares over the past year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.48%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.88%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Mar. 31, 2025          
Lowest Quarterly Return (0.59%)          
Performance Table Heading Average Annual Returns          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2070 Fund | After Taxes on Distributions | Fidelity Sustainable Target Date 2070 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   20.74%     15.64% [56]  
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2070 Fund | After Taxes on Distributions and Sales | Fidelity Sustainable Target Date 2070 Fund            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   12.83%     12.40% [56]  
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2070 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%     17.78%  
FidelitySustainableTargetDateFunds-ComboRetailPro | Fidelity Sustainable Target Date 2070 Fund | IXTP0            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2070 Composite Index℠        
Average Annual Return, Percent   21.00%     17.21%  
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date Retirement Fund | Fidelity Advisor Sustainable Target Date Retirement Fund - Class A            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 5.75%          
Maximum Deferred Sales Charge (as a percentage) [57] 0.00%          
Management Fees (as a percentage of Assets) [58] 0.41%          
Distribution and Service (12b-1) Fees 0.25%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [58] 0.66%          
Expense Example, with Redemption, 1 Year $ 639          
Expense Example, with Redemption, 3 Years 774          
Expense Example, with Redemption, 5 Years 922          
Expense Example, with Redemption, 10 Years 1,350          
Expense Example, No Redemption, 1 Year 639          
Expense Example, No Redemption, 3 Years 774          
Expense Example, No Redemption, 5 Years 922          
Expense Example, No Redemption, 10 Years $ 1,350          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   3.04%       3.93% [59]
Annual Return [Percent]     9.33% 3.76%    
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date Retirement Fund | Fidelity Advisor Sustainable Target Date Retirement Fund - Class M            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 3.50%          
Maximum Deferred Sales Charge (as a percentage) [57] 0.00%          
Management Fees (as a percentage of Assets) [58] 0.41%          
Distribution and Service (12b-1) Fees 0.50%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [58] 0.91%          
Expense Example, with Redemption, 1 Year $ 440          
Expense Example, with Redemption, 3 Years 630          
Expense Example, with Redemption, 5 Years 836          
Expense Example, with Redemption, 10 Years 1,430          
Expense Example, No Redemption, 1 Year 440          
Expense Example, No Redemption, 3 Years 630          
Expense Example, No Redemption, 5 Years 836          
Expense Example, No Redemption, 10 Years $ 1,430          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   5.24%       4.61% [60]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date Retirement Fund | Fidelity Advisor Sustainable Target Date Retirement Fund - Class C            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) [61] 1.00%          
Management Fees (as a percentage of Assets) [58] 0.41%          
Distribution and Service (12b-1) Fees 1.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [58] 1.41%          
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.          
Expense Example, with Redemption, 1 Year $ 244          
Expense Example, with Redemption, 3 Years 446          
Expense Example, with Redemption, 5 Years 771          
Expense Example, with Redemption, 10 Years 1,486          
Expense Example, No Redemption, 1 Year 144          
Expense Example, No Redemption, 3 Years 446          
Expense Example, No Redemption, 5 Years 771          
Expense Example, No Redemption, 10 Years $ 1,486          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   7.53%       5.50% [62]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date Retirement Fund | Fidelity Advisor Sustainable Target Date Retirement Fund - Class I            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [58] 0.41%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [58] 0.41%          
Expense Example, with Redemption, 1 Year $ 42          
Expense Example, with Redemption, 3 Years 132          
Expense Example, with Redemption, 5 Years 230          
Expense Example, with Redemption, 10 Years 518          
Expense Example, No Redemption, 1 Year 42          
Expense Example, No Redemption, 3 Years 132          
Expense Example, No Redemption, 5 Years 230          
Expense Example, No Redemption, 10 Years $ 518          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   9.59%       6.55% [63]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date Retirement Fund | Fidelity Advisor Sustainable Target Date Retirement Fund - Class Z            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [58] 0.31%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [58] 0.31%          
Expense Example, with Redemption, 1 Year $ 32          
Expense Example, with Redemption, 3 Years 100          
Expense Example, with Redemption, 5 Years 174          
Expense Example, with Redemption, 10 Years 393          
Expense Example, No Redemption, 1 Year 32          
Expense Example, No Redemption, 3 Years 100          
Expense Example, No Redemption, 5 Years 174          
Expense Example, No Redemption, 10 Years $ 393          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   9.71%       6.66% [64]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date Retirement Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date Retirement Fund /Fidelity Advisor® Sustainable Target Date Retirement Fund A, M, C, I, Z            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date Retirement Fund seeks high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus and in the sales charge waiver appendix to the prospectus.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 36 % of the average value of its portfolio.          
Portfolio Turnover, Rate 36.00%          
Expenses Deferred Charges [Text Block] Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.          
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus          
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a stable neutral asset allocation strategy. A revised neutral asset allocation strategy (approximately 18% in U.S. equity funds, 12% in international equity funds, 33% in U.S. investment grade bond funds, 5% in international bond funds, 2% in long-term treasury bond funds, 24% in short-term inflation protected bond funds, and 7% in short-term funds; allocations do not add to 100% due to rounding) is expected to take effect by the end of the first quarter of 2027. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] institutional.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.21%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Sep. 30, 2024          
Highest Quarterly Return 4.49%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.49%)          
Performance Table Heading Average Annual Returns          
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date Retirement Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Target Date Retirement Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   1.77%       2.65% [59]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date Retirement Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Target Date Retirement Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   1.88%       2.50% [59]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date Retirement Fund | IXUFW            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date Retirement Composite Index℠        
Average Annual Return, Percent   9.31%       6.91%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date Retirement Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2010 Fund | Fidelity Advisor Sustainable Target Date 2010 Fund - Class A            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 5.75%          
Maximum Deferred Sales Charge (as a percentage) [65] 0.00%          
Management Fees (as a percentage of Assets) [66] 0.41%          
Distribution and Service (12b-1) Fees 0.25%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [66] 0.66%          
Expense Example, with Redemption, 1 Year $ 639          
Expense Example, with Redemption, 3 Years 774          
Expense Example, with Redemption, 5 Years 922          
Expense Example, with Redemption, 10 Years 1,350          
Expense Example, No Redemption, 1 Year 639          
Expense Example, No Redemption, 3 Years 774          
Expense Example, No Redemption, 5 Years 922          
Expense Example, No Redemption, 10 Years $ 1,350          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   3.98%       4.91% [67]
Annual Return [Percent]     10.32% 4.49%    
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2010 Fund | Fidelity Advisor Sustainable Target Date 2010 Fund - Class M            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 3.50%          
Maximum Deferred Sales Charge (as a percentage) [65] 0.00%          
Management Fees (as a percentage of Assets) [66] 0.41%          
Distribution and Service (12b-1) Fees 0.50%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [66] 0.91%          
Expense Example, with Redemption, 1 Year $ 440          
Expense Example, with Redemption, 3 Years 630          
Expense Example, with Redemption, 5 Years 836          
Expense Example, with Redemption, 10 Years 1,430          
Expense Example, No Redemption, 1 Year 440          
Expense Example, No Redemption, 3 Years 630          
Expense Example, No Redemption, 5 Years 836          
Expense Example, No Redemption, 10 Years $ 1,430          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   6.17%       5.60% [68]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2010 Fund | Fidelity Advisor Sustainable Target Date 2010 Fund - Class C            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) [69] 1.00%          
Management Fees (as a percentage of Assets) [66] 0.41%          
Distribution and Service (12b-1) Fees 1.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [66] 1.41%          
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.          
Expense Example, with Redemption, 1 Year $ 244          
Expense Example, with Redemption, 3 Years 446          
Expense Example, with Redemption, 5 Years 771          
Expense Example, with Redemption, 10 Years 1,486          
Expense Example, No Redemption, 1 Year 144          
Expense Example, No Redemption, 3 Years 446          
Expense Example, No Redemption, 5 Years 771          
Expense Example, No Redemption, 10 Years $ 1,486          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   8.45%       6.49% [70]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2010 Fund | Fidelity Advisor Sustainable Target Date 2010 Fund - Class I            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [66] 0.41%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [66] 0.41%          
Expense Example, with Redemption, 1 Year $ 42          
Expense Example, with Redemption, 3 Years 132          
Expense Example, with Redemption, 5 Years 230          
Expense Example, with Redemption, 10 Years 518          
Expense Example, No Redemption, 1 Year 42          
Expense Example, No Redemption, 3 Years 132          
Expense Example, No Redemption, 5 Years 230          
Expense Example, No Redemption, 10 Years $ 518          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   10.56%       7.57% [71]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2010 Fund | Fidelity Advisor Sustainable Target Date 2010 Fund - Class Z            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [66] 0.31%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [66] 0.31%          
Expense Example, with Redemption, 1 Year $ 32          
Expense Example, with Redemption, 3 Years 100          
Expense Example, with Redemption, 5 Years 174          
Expense Example, with Redemption, 10 Years 393          
Expense Example, No Redemption, 1 Year 32          
Expense Example, No Redemption, 3 Years 100          
Expense Example, No Redemption, 5 Years 174          
Expense Example, No Redemption, 10 Years $ 393          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   10.67%       7.68% [72]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2010 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2010 Fund /Fidelity Advisor® Sustainable Target Date 2010 Fund A, M, C, I, Z            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2010 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus and in the sales charge waiver appendix to the prospectus.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 30 % of the average value of its portfolio.          
Portfolio Turnover, Rate 30.00%          
Expenses Deferred Charges [Text Block] Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.          
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus          
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2010. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who retired in or within a few years of 2010 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] institutional.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.27%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Sep. 30, 2024          
Highest Quarterly Return 4.81%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.71%)          
Performance Table Heading Average Annual Returns          
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2010 Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Target Date 2010 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   2.72%       3.64% [67]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2010 Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Target Date 2010 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   2.51%       3.27% [67]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2010 Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2010 Fund | IXUFX            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2010 Composite Index℠        
Average Annual Return, Percent   10.22%       7.87%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2015 Fund | Fidelity Advisor Sustainable Target Date 2015 Fund - Class A            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 5.75%          
Maximum Deferred Sales Charge (as a percentage) [73] 0.00%          
Management Fees (as a percentage of Assets) [74] 0.42%          
Distribution and Service (12b-1) Fees 0.25%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [74] 0.67%          
Expense Example, with Redemption, 1 Year $ 640          
Expense Example, with Redemption, 3 Years 777          
Expense Example, with Redemption, 5 Years 927          
Expense Example, with Redemption, 10 Years 1,362          
Expense Example, No Redemption, 1 Year 640          
Expense Example, No Redemption, 3 Years 777          
Expense Example, No Redemption, 5 Years 927          
Expense Example, No Redemption, 10 Years $ 1,362          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   5.48%       6.17% [75]
Annual Return [Percent]     11.92% 5.47%    
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2015 Fund | Fidelity Advisor Sustainable Target Date 2015 Fund - Class M            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 3.50%          
Maximum Deferred Sales Charge (as a percentage) [73] 0.00%          
Management Fees (as a percentage of Assets) [74] 0.42%          
Distribution and Service (12b-1) Fees 0.50%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [74] 0.92%          
Expense Example, with Redemption, 1 Year $ 441          
Expense Example, with Redemption, 3 Years 633          
Expense Example, with Redemption, 5 Years 841          
Expense Example, with Redemption, 10 Years 1,442          
Expense Example, No Redemption, 1 Year 441          
Expense Example, No Redemption, 3 Years 633          
Expense Example, No Redemption, 5 Years 841          
Expense Example, No Redemption, 10 Years $ 1,442          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   7.61%       6.83% [76]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2015 Fund | Fidelity Advisor Sustainable Target Date 2015 Fund - Class C            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) [77] 1.00%          
Management Fees (as a percentage of Assets) [74] 0.42%          
Distribution and Service (12b-1) Fees 1.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [74] 1.42%          
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.          
Expense Example, with Redemption, 1 Year $ 245          
Expense Example, with Redemption, 3 Years 449          
Expense Example, with Redemption, 5 Years 776          
Expense Example, with Redemption, 10 Years 1,497          
Expense Example, No Redemption, 1 Year 145          
Expense Example, No Redemption, 3 Years 449          
Expense Example, No Redemption, 5 Years 776          
Expense Example, No Redemption, 10 Years $ 1,497          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   9.99%       7.76% [78]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2015 Fund | Fidelity Advisor Sustainable Target Date 2015 Fund - Class I            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [74] 0.42%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [74] 0.42%          
Expense Example, with Redemption, 1 Year $ 43          
Expense Example, with Redemption, 3 Years 135          
Expense Example, with Redemption, 5 Years 235          
Expense Example, with Redemption, 10 Years 530          
Expense Example, No Redemption, 1 Year 43          
Expense Example, No Redemption, 3 Years 135          
Expense Example, No Redemption, 5 Years 235          
Expense Example, No Redemption, 10 Years $ 530          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   12.14%       8.83% [79]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2015 Fund | Fidelity Advisor Sustainable Target Date 2015 Fund - Class Z            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [74] 0.32%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [74] 0.32%          
Expense Example, with Redemption, 1 Year $ 33          
Expense Example, with Redemption, 3 Years 103          
Expense Example, with Redemption, 5 Years 180          
Expense Example, with Redemption, 10 Years 406          
Expense Example, No Redemption, 1 Year 33          
Expense Example, No Redemption, 3 Years 103          
Expense Example, No Redemption, 5 Years 180          
Expense Example, No Redemption, 10 Years $ 406          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   12.25%       8.93% [80]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2015 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2015 Fund /Fidelity Advisor® Sustainable Target Date 2015 Fund A, M, C, I, Z            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2015 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus and in the sales charge waiver appendix to the prospectus.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Deferred Charges [Text Block] Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.          
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus          
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2015. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who retired in or within a few years of 2015 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] institutional.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.52%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Sep. 30, 2024          
Highest Quarterly Return 5.10%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.87%)          
Performance Table Heading Average Annual Returns          
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2015 Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Target Date 2015 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   4.38%       4.98% [75]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2015 Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Target Date 2015 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   3.36%       4.28% [75]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2015 Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2015 Fund | IXUFY            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2015 Composite Index℠        
Average Annual Return, Percent   11.75%       9.11%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2020 Fund | Fidelity Advisor Sustainable Target Date 2020 Fund - Class A            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 5.75%          
Maximum Deferred Sales Charge (as a percentage) [81] 0.00%          
Management Fees (as a percentage of Assets) [82] 0.43%          
Distribution and Service (12b-1) Fees 0.25%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [82] 0.68%          
Expense Example, with Redemption, 1 Year $ 640          
Expense Example, with Redemption, 3 Years 780          
Expense Example, with Redemption, 5 Years 932          
Expense Example, with Redemption, 10 Years 1,373          
Expense Example, No Redemption, 1 Year 640          
Expense Example, No Redemption, 3 Years 780          
Expense Example, No Redemption, 5 Years 932          
Expense Example, No Redemption, 10 Years $ 1,373          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   6.84%       7.36% [83]
Annual Return [Percent]     13.36% 6.31%    
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2020 Fund | Fidelity Advisor Sustainable Target Date 2020 Fund - Class M            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 3.50%          
Maximum Deferred Sales Charge (as a percentage) [81] 0.00%          
Management Fees (as a percentage of Assets) [82] 0.43%          
Distribution and Service (12b-1) Fees 0.50%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [82] 0.93%          
Expense Example, with Redemption, 1 Year $ 442          
Expense Example, with Redemption, 3 Years 636          
Expense Example, with Redemption, 5 Years 847          
Expense Example, with Redemption, 10 Years 1,453          
Expense Example, No Redemption, 1 Year 442          
Expense Example, No Redemption, 3 Years 636          
Expense Example, No Redemption, 5 Years 847          
Expense Example, No Redemption, 10 Years $ 1,453          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   9.08%       8.06% [84]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2020 Fund | Fidelity Advisor Sustainable Target Date 2020 Fund - Class C            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) [85] 1.00%          
Management Fees (as a percentage of Assets) [82] 0.43%          
Distribution and Service (12b-1) Fees 1.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [82] 1.43%          
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.          
Expense Example, with Redemption, 1 Year $ 246          
Expense Example, with Redemption, 3 Years 452          
Expense Example, with Redemption, 5 Years 782          
Expense Example, with Redemption, 10 Years 1,509          
Expense Example, No Redemption, 1 Year 146          
Expense Example, No Redemption, 3 Years 452          
Expense Example, No Redemption, 5 Years 782          
Expense Example, No Redemption, 10 Years $ 1,509          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   11.53%       9.01% [86]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2020 Fund | Fidelity Advisor Sustainable Target Date 2020 Fund - Class I            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [82] 0.43%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [82] 0.43%          
Expense Example, with Redemption, 1 Year $ 44          
Expense Example, with Redemption, 3 Years 138          
Expense Example, with Redemption, 5 Years 241          
Expense Example, with Redemption, 10 Years 542          
Expense Example, No Redemption, 1 Year 44          
Expense Example, No Redemption, 3 Years 138          
Expense Example, No Redemption, 5 Years 241          
Expense Example, No Redemption, 10 Years $ 542          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   13.62%       10.08% [87]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2020 Fund | Fidelity Advisor Sustainable Target Date 2020 Fund - Class Z            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [82] 0.33%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [82] 0.33%          
Expense Example, with Redemption, 1 Year $ 34          
Expense Example, with Redemption, 3 Years 106          
Expense Example, with Redemption, 5 Years 185          
Expense Example, with Redemption, 10 Years 418          
Expense Example, No Redemption, 1 Year 34          
Expense Example, No Redemption, 3 Years 106          
Expense Example, No Redemption, 5 Years 185          
Expense Example, No Redemption, 10 Years $ 418          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   13.83%       10.21% [88]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2020 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2020 Fund /Fidelity Advisor® Sustainable Target Date 2020 Fund A, M, C, I, Z            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2020 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus and in the sales charge waiver appendix to the prospectus.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 31 % of the average value of its portfolio.          
Portfolio Turnover, Rate 31.00%          
Expenses Deferred Charges [Text Block] Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.          
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus          
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2020. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who retired in or within a few years of 2020 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] institutional.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.58%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 5.83%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (3.15%)          
Performance Table Heading Average Annual Returns          
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2020 Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Target Date 2020 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   5.93%       6.42% [83]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2020 Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Target Date 2020 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   4.23%       5.34% [83]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2020 Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2020 Fund | IXUFZ            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2020 Composite Index℠        
Average Annual Return, Percent   13.30%       10.36%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2025 Fund | Fidelity Advisor Sustainable Target Date 2025 Fund - Class A            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 5.75%          
Maximum Deferred Sales Charge (as a percentage) [89] 0.00%          
Management Fees (as a percentage of Assets) [90] 0.44%          
Distribution and Service (12b-1) Fees 0.25%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [90] 0.69%          
Expense Example, with Redemption, 1 Year $ 641          
Expense Example, with Redemption, 3 Years 783          
Expense Example, with Redemption, 5 Years 937          
Expense Example, with Redemption, 10 Years 1,384          
Expense Example, No Redemption, 1 Year 641          
Expense Example, No Redemption, 3 Years 783          
Expense Example, No Redemption, 5 Years 937          
Expense Example, No Redemption, 10 Years $ 1,384          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   8.11%       8.46% [91]
Annual Return [Percent]     14.71% 7.10%    
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2025 Fund | Fidelity Advisor Sustainable Target Date 2025 Fund - Class M            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 3.50%          
Maximum Deferred Sales Charge (as a percentage) [89] 0.00%          
Management Fees (as a percentage of Assets) [90] 0.44%          
Distribution and Service (12b-1) Fees 0.50%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [90] 0.94%          
Expense Example, with Redemption, 1 Year $ 443          
Expense Example, with Redemption, 3 Years 639          
Expense Example, with Redemption, 5 Years 852          
Expense Example, with Redemption, 10 Years 1,464          
Expense Example, No Redemption, 1 Year 443          
Expense Example, No Redemption, 3 Years 639          
Expense Example, No Redemption, 5 Years 852          
Expense Example, No Redemption, 10 Years $ 1,464          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   10.50%       9.18% [92]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2025 Fund | Fidelity Advisor Sustainable Target Date 2025 Fund - Class C            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) [93] 1.00%          
Management Fees (as a percentage of Assets) [90] 0.44%          
Distribution and Service (12b-1) Fees 1.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [90] 1.44%          
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.          
Expense Example, with Redemption, 1 Year $ 247          
Expense Example, with Redemption, 3 Years 456          
Expense Example, with Redemption, 5 Years 787          
Expense Example, with Redemption, 10 Years 1,520          
Expense Example, No Redemption, 1 Year 147          
Expense Example, No Redemption, 3 Years 456          
Expense Example, No Redemption, 5 Years 787          
Expense Example, No Redemption, 10 Years $ 1,520          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   12.97%       10.10% [94]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2025 Fund | Fidelity Advisor Sustainable Target Date 2025 Fund - Class I            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [90] 0.44%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [90] 0.44%          
Expense Example, with Redemption, 1 Year $ 45          
Expense Example, with Redemption, 3 Years 141          
Expense Example, with Redemption, 5 Years 246          
Expense Example, with Redemption, 10 Years 555          
Expense Example, No Redemption, 1 Year 45          
Expense Example, No Redemption, 3 Years 141          
Expense Example, No Redemption, 5 Years 246          
Expense Example, No Redemption, 10 Years $ 555          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   15.05%       11.19% [95]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2025 Fund | Fidelity Advisor Sustainable Target Date 2025 Fund - Class Z            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [90] 0.34%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [90] 0.34%          
Expense Example, with Redemption, 1 Year $ 35          
Expense Example, with Redemption, 3 Years 109          
Expense Example, with Redemption, 5 Years 191          
Expense Example, with Redemption, 10 Years 431          
Expense Example, No Redemption, 1 Year 35          
Expense Example, No Redemption, 3 Years 109          
Expense Example, No Redemption, 5 Years 191          
Expense Example, No Redemption, 10 Years $ 431          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   15.24%       11.32% [96]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2025 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2025 Fund /Fidelity Advisor® Sustainable Target Date 2025 Fund A, M, C, I, Z            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2025 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus and in the sales charge waiver appendix to the prospectus.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 29 % of the average value of its portfolio.          
Portfolio Turnover, Rate 29.00%          
Expenses Deferred Charges [Text Block] Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.          
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus          
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2025. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2025 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] institutional.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.80%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 6.54%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (3.20%)          
Performance Table Heading Average Annual Returns          
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2025 Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Target Date 2025 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   7.47%       7.70% [91]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2025 Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Target Date 2025 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   4.94%       6.27% [91]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2025 Fund | IXUG2            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2025 Composite Index℠        
Average Annual Return, Percent   14.75%       11.51%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2025 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2030 Fund | Fidelity Advisor Sustainable Target Date 2030 Fund - Class A            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 5.75%          
Maximum Deferred Sales Charge (as a percentage) [97] 0.00%          
Management Fees (as a percentage of Assets) [98] 0.45%          
Distribution and Service (12b-1) Fees 0.25%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [98] 0.70%          
Expense Example, with Redemption, 1 Year $ 642          
Expense Example, with Redemption, 3 Years 786          
Expense Example, with Redemption, 5 Years 942          
Expense Example, with Redemption, 10 Years 1,395          
Expense Example, No Redemption, 1 Year 642          
Expense Example, No Redemption, 3 Years 786          
Expense Example, No Redemption, 5 Years 942          
Expense Example, No Redemption, 10 Years $ 1,395          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   9.07%       9.54% [99]
Annual Return [Percent]     15.73% 8.08%    
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2030 Fund | Fidelity Advisor Sustainable Target Date 2030 Fund - Class M            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 3.50%          
Maximum Deferred Sales Charge (as a percentage) [97] 0.00%          
Management Fees (as a percentage of Assets) [98] 0.45%          
Distribution and Service (12b-1) Fees 0.50%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [98] 0.95%          
Expense Example, with Redemption, 1 Year $ 444          
Expense Example, with Redemption, 3 Years 642          
Expense Example, with Redemption, 5 Years 857          
Expense Example, with Redemption, 10 Years 1,476          
Expense Example, No Redemption, 1 Year 444          
Expense Example, No Redemption, 3 Years 642          
Expense Example, No Redemption, 5 Years 857          
Expense Example, No Redemption, 10 Years $ 1,476          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   11.44%       10.27% [100]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2030 Fund | Fidelity Advisor Sustainable Target Date 2030 Fund - Class C            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) [101] 1.00%          
Management Fees (as a percentage of Assets) [98] 0.45%          
Distribution and Service (12b-1) Fees 1.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [98] 1.45%          
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.          
Expense Example, with Redemption, 1 Year $ 248          
Expense Example, with Redemption, 3 Years 459          
Expense Example, with Redemption, 5 Years 792          
Expense Example, with Redemption, 10 Years 1,531          
Expense Example, No Redemption, 1 Year 148          
Expense Example, No Redemption, 3 Years 459          
Expense Example, No Redemption, 5 Years 792          
Expense Example, No Redemption, 10 Years $ 1,531          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   13.89%       11.18% [102]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2030 Fund | Fidelity Advisor Sustainable Target Date 2030 Fund - Class I            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [98] 0.45%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [98] 0.45%          
Expense Example, with Redemption, 1 Year $ 46          
Expense Example, with Redemption, 3 Years 144          
Expense Example, with Redemption, 5 Years 252          
Expense Example, with Redemption, 10 Years 567          
Expense Example, No Redemption, 1 Year 46          
Expense Example, No Redemption, 3 Years 144          
Expense Example, No Redemption, 5 Years 252          
Expense Example, No Redemption, 10 Years $ 567          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   16.08%       12.31% [103]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2030 Fund | Fidelity Advisor Sustainable Target Date 2030 Fund - Class Z            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [98] 0.35%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [98] 0.35%          
Expense Example, with Redemption, 1 Year $ 36          
Expense Example, with Redemption, 3 Years 113          
Expense Example, with Redemption, 5 Years 197          
Expense Example, with Redemption, 10 Years 443          
Expense Example, No Redemption, 1 Year 36          
Expense Example, No Redemption, 3 Years 113          
Expense Example, No Redemption, 5 Years 197          
Expense Example, No Redemption, 10 Years $ 443          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   16.12%       12.41% [104]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2030 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2030 Fund /Fidelity Advisor® Sustainable Target Date 2030 Fund A, M, C, I, Z            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2030 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus and in the sales charge waiver appendix to the prospectus.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 43 % of the average value of its portfolio.          
Portfolio Turnover, Rate 43.00%          
Expenses Deferred Charges [Text Block] Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.          
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus          
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2030. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2030 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] institutional.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.94%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 7.34%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (3.08%)          
Performance Table Heading Average Annual Returns          
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2030 Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Target Date 2030 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   8.46%       8.87% [99]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2030 Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Target Date 2030 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   5.55%       7.18% [99]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2030 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2030 Fund | IXUG3            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2030 Composite Index℠        
Average Annual Return, Percent   15.73%       12.60%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2035 Fund | Fidelity Advisor Sustainable Target Date 2035 Fund - Class A            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 5.75%          
Maximum Deferred Sales Charge (as a percentage) [105] 0.00%          
Management Fees (as a percentage of Assets) [106] 0.47%          
Distribution and Service (12b-1) Fees 0.25%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [106] 0.72%          
Expense Example, with Redemption, 1 Year $ 644          
Expense Example, with Redemption, 3 Years 792          
Expense Example, with Redemption, 5 Years 953          
Expense Example, with Redemption, 10 Years 1,418          
Expense Example, No Redemption, 1 Year 644          
Expense Example, No Redemption, 3 Years 792          
Expense Example, No Redemption, 5 Years 953          
Expense Example, No Redemption, 10 Years $ 1,418          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   10.28%       11.26% [107]
Annual Return [Percent]     17.01% 9.84%    
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2035 Fund | Fidelity Advisor Sustainable Target Date 2035 Fund - Class M            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 3.50%          
Maximum Deferred Sales Charge (as a percentage) [105] 0.00%          
Management Fees (as a percentage of Assets) [106] 0.47%          
Distribution and Service (12b-1) Fees 0.50%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [106] 0.97%          
Expense Example, with Redemption, 1 Year $ 445          
Expense Example, with Redemption, 3 Years 648          
Expense Example, with Redemption, 5 Years 868          
Expense Example, with Redemption, 10 Years 1,498          
Expense Example, No Redemption, 1 Year 445          
Expense Example, No Redemption, 3 Years 648          
Expense Example, No Redemption, 5 Years 868          
Expense Example, No Redemption, 10 Years $ 1,498          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   12.71%       12.00% [108]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2035 Fund | Fidelity Advisor Sustainable Target Date 2035 Fund - Class C            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) [109] 1.00%          
Management Fees (as a percentage of Assets) [106] 0.47%          
Distribution and Service (12b-1) Fees 1.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [106] 1.47%          
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.          
Expense Example, with Redemption, 1 Year $ 250          
Expense Example, with Redemption, 3 Years 465          
Expense Example, with Redemption, 5 Years 803          
Expense Example, with Redemption, 10 Years 1,554          
Expense Example, No Redemption, 1 Year 150          
Expense Example, No Redemption, 3 Years 465          
Expense Example, No Redemption, 5 Years 803          
Expense Example, No Redemption, 10 Years $ 1,554          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   15.25%       12.96% [110]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2035 Fund | Fidelity Advisor Sustainable Target Date 2035 Fund - Class I            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [106] 0.47%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [106] 0.47%          
Expense Example, with Redemption, 1 Year $ 48          
Expense Example, with Redemption, 3 Years 151          
Expense Example, with Redemption, 5 Years 263          
Expense Example, with Redemption, 10 Years 591          
Expense Example, No Redemption, 1 Year 48          
Expense Example, No Redemption, 3 Years 151          
Expense Example, No Redemption, 5 Years 263          
Expense Example, No Redemption, 10 Years $ 591          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   17.35%       14.08% [111]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2035 Fund | Fidelity Advisor Sustainable Target Date 2035 Fund - Class Z            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [106] 0.37%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [106] 0.37%          
Expense Example, with Redemption, 1 Year $ 38          
Expense Example, with Redemption, 3 Years 119          
Expense Example, with Redemption, 5 Years 208          
Expense Example, with Redemption, 10 Years 468          
Expense Example, No Redemption, 1 Year 38          
Expense Example, No Redemption, 3 Years 119          
Expense Example, No Redemption, 5 Years 208          
Expense Example, No Redemption, 10 Years $ 468          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   17.50%       14.19% [112]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2035 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2035 Fund /Fidelity Advisor® Sustainable Target Date 2035 Fund A, M, C, I, Z            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2035 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus and in the sales charge waiver appendix to the prospectus.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 26 % of the average value of its portfolio.          
Portfolio Turnover, Rate 26.00%          
Expenses Deferred Charges [Text Block] Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.          
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus          
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2035. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2035 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] institutional.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.04%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 8.32%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.86%)          
Performance Table Heading Average Annual Returns          
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2035 Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Target Date 2035 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   9.74%       10.69% [107]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2035 Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Target Date 2035 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   6.29%       8.59% [107]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2035 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2035 Fund | IXUG5            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2035 Composite Index℠        
Average Annual Return, Percent   17.08%       14.32%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2040 Fund | Fidelity Advisor Sustainable Target Date 2040 Fund - Class A            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 5.75%          
Maximum Deferred Sales Charge (as a percentage) [113] 0.00%          
Management Fees (as a percentage of Assets) [114] 0.48%          
Distribution and Service (12b-1) Fees 0.25%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [114] 0.73%          
Expense Example, with Redemption, 1 Year $ 645          
Expense Example, with Redemption, 3 Years 795          
Expense Example, with Redemption, 5 Years 958          
Expense Example, with Redemption, 10 Years 1,429          
Expense Example, No Redemption, 1 Year 645          
Expense Example, No Redemption, 3 Years 795          
Expense Example, No Redemption, 5 Years 958          
Expense Example, No Redemption, 10 Years $ 1,429          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   12.70%       13.56% [115]
Annual Return [Percent]     19.58% 11.83%    
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2040 Fund | Fidelity Advisor Sustainable Target Date 2040 Fund - Class M            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 3.50%          
Maximum Deferred Sales Charge (as a percentage) [113] 0.00%          
Management Fees (as a percentage of Assets) [114] 0.48%          
Distribution and Service (12b-1) Fees 0.50%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [114] 0.98%          
Expense Example, with Redemption, 1 Year $ 446          
Expense Example, with Redemption, 3 Years 651          
Expense Example, with Redemption, 5 Years 873          
Expense Example, with Redemption, 10 Years 1,509          
Expense Example, No Redemption, 1 Year 446          
Expense Example, No Redemption, 3 Years 651          
Expense Example, No Redemption, 5 Years 873          
Expense Example, No Redemption, 10 Years $ 1,509          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   15.11%       14.29% [116]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2040 Fund | Fidelity Advisor Sustainable Target Date 2040 Fund - Class C            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) [117] 1.00%          
Management Fees (as a percentage of Assets) [114] 0.48%          
Distribution and Service (12b-1) Fees 1.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [114] 1.48%          
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.          
Expense Example, with Redemption, 1 Year $ 251          
Expense Example, with Redemption, 3 Years 468          
Expense Example, with Redemption, 5 Years 808          
Expense Example, with Redemption, 10 Years 1,565          
Expense Example, No Redemption, 1 Year 151          
Expense Example, No Redemption, 3 Years 468          
Expense Example, No Redemption, 5 Years 808          
Expense Example, No Redemption, 10 Years $ 1,565          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   17.65%       15.27% [118]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2040 Fund | Fidelity Advisor Sustainable Target Date 2040 Fund - Class I            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [114] 0.48%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [114] 0.48%          
Expense Example, with Redemption, 1 Year $ 49          
Expense Example, with Redemption, 3 Years 154          
Expense Example, with Redemption, 5 Years 269          
Expense Example, with Redemption, 10 Years 604          
Expense Example, No Redemption, 1 Year 49          
Expense Example, No Redemption, 3 Years 154          
Expense Example, No Redemption, 5 Years 269          
Expense Example, No Redemption, 10 Years $ 604          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   19.85%       16.44% [119]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2040 Fund | Fidelity Advisor Sustainable Target Date 2040 Fund - Class Z            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [114] 0.38%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [114] 0.38%          
Expense Example, with Redemption, 1 Year $ 39          
Expense Example, with Redemption, 3 Years 122          
Expense Example, with Redemption, 5 Years 213          
Expense Example, with Redemption, 10 Years 480          
Expense Example, No Redemption, 1 Year 39          
Expense Example, No Redemption, 3 Years 122          
Expense Example, No Redemption, 5 Years 213          
Expense Example, No Redemption, 10 Years $ 480          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   19.95%       16.55% [120]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2040 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2040 Fund /Fidelity Advisor® Sustainable Target Date 2040 Fund A, M, C, I, Z            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2040 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus and in the sales charge waiver appendix to the prospectus.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Deferred Charges [Text Block] Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.          
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus          
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2040. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2040 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] institutional.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.33%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.02%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.72%)          
Performance Table Heading Average Annual Returns          
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2040 Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Target Date 2040 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   12.31%       13.15% [115]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2040 Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Target Date 2040 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   7.77%       10.51% [115]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2040 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2040 Fund | IXUG8            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2040 Composite Index℠        
Average Annual Return, Percent   19.54%       16.61%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2045 Fund | Fidelity Advisor Sustainable Target Date 2045 Fund - Class A            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 5.75%          
Maximum Deferred Sales Charge (as a percentage) [121] 0.00%          
Management Fees (as a percentage of Assets) [122] 0.49%          
Distribution and Service (12b-1) Fees 0.25%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [122] 0.74%          
Expense Example, with Redemption, 1 Year $ 646          
Expense Example, with Redemption, 3 Years 798          
Expense Example, with Redemption, 5 Years 963          
Expense Example, with Redemption, 10 Years 1,441          
Expense Example, No Redemption, 1 Year 646          
Expense Example, No Redemption, 3 Years 798          
Expense Example, No Redemption, 5 Years 963          
Expense Example, No Redemption, 10 Years $ 1,441          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   13.91%       14.51% [123]
Annual Return [Percent]     20.86% 12.67%    
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2045 Fund | Fidelity Advisor Sustainable Target Date 2045 Fund - Class M            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 3.50%          
Maximum Deferred Sales Charge (as a percentage) [121] 0.00%          
Management Fees (as a percentage of Assets) [122] 0.49%          
Distribution and Service (12b-1) Fees 0.50%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [122] 0.99%          
Expense Example, with Redemption, 1 Year $ 447          
Expense Example, with Redemption, 3 Years 654          
Expense Example, with Redemption, 5 Years 878          
Expense Example, with Redemption, 10 Years 1,521          
Expense Example, No Redemption, 1 Year 447          
Expense Example, No Redemption, 3 Years 654          
Expense Example, No Redemption, 5 Years 878          
Expense Example, No Redemption, 10 Years $ 1,521          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   16.32%       15.24% [124]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2045 Fund | Fidelity Advisor Sustainable Target Date 2045 Fund - Class C            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) [125] 1.00%          
Management Fees (as a percentage of Assets) [122] 0.49%          
Distribution and Service (12b-1) Fees 1.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [122] 1.49%          
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.          
Expense Example, with Redemption, 1 Year $ 252          
Expense Example, with Redemption, 3 Years 471          
Expense Example, with Redemption, 5 Years 813          
Expense Example, with Redemption, 10 Years 1,576          
Expense Example, No Redemption, 1 Year 152          
Expense Example, No Redemption, 3 Years 471          
Expense Example, No Redemption, 5 Years 813          
Expense Example, No Redemption, 10 Years $ 1,576          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   18.96%       16.24% [126]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2045 Fund | Fidelity Advisor Sustainable Target Date 2045 Fund - Class I            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [122] 0.49%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [122] 0.49%          
Expense Example, with Redemption, 1 Year $ 50          
Expense Example, with Redemption, 3 Years 157          
Expense Example, with Redemption, 5 Years 274          
Expense Example, with Redemption, 10 Years 616          
Expense Example, No Redemption, 1 Year 50          
Expense Example, No Redemption, 3 Years 157          
Expense Example, No Redemption, 5 Years 274          
Expense Example, No Redemption, 10 Years $ 616          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.14%       17.40% [127]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2045 Fund | Fidelity Advisor Sustainable Target Date 2045 Fund - Class Z            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [122] 0.39%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [122] 0.39%          
Expense Example, with Redemption, 1 Year $ 40          
Expense Example, with Redemption, 3 Years 125          
Expense Example, with Redemption, 5 Years 219          
Expense Example, with Redemption, 10 Years 493          
Expense Example, No Redemption, 1 Year 40          
Expense Example, No Redemption, 3 Years 125          
Expense Example, No Redemption, 5 Years 219          
Expense Example, No Redemption, 10 Years $ 493          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.19%       17.51% [128]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2045 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2045 Fund /Fidelity Advisor® Sustainable Target Date 2045 Fund A, M, C, I, Z            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2045 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus and in the sales charge waiver appendix to the prospectus.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Deferred Charges [Text Block] Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.          
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus          
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2045. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2045 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] institutional.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.50%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.77%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.58%)          
Performance Table Heading Average Annual Returns          
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2045 Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Target Date 2045 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   13.54%       14.14% [123]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2045 Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Target Date 2045 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   8.51%       11.30% [123]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2045 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2045 Fund | IXUG9            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2045 Composite Index℠        
Average Annual Return, Percent   20.97%       17.60%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2050 Fund | Fidelity Advisor Sustainable Target Date 2050 Fund - Class A            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 5.75%          
Maximum Deferred Sales Charge (as a percentage) [129] 0.00%          
Management Fees (as a percentage of Assets) [130] 0.49%          
Distribution and Service (12b-1) Fees 0.25%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [130] 0.74%          
Expense Example, with Redemption, 1 Year $ 646          
Expense Example, with Redemption, 3 Years 798          
Expense Example, with Redemption, 5 Years 963          
Expense Example, with Redemption, 10 Years 1,441          
Expense Example, No Redemption, 1 Year 646          
Expense Example, No Redemption, 3 Years 798          
Expense Example, No Redemption, 5 Years 963          
Expense Example, No Redemption, 10 Years $ 1,441          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   13.90%       14.52% [131]
Annual Return [Percent]     20.85% 12.71%    
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2050 Fund | Fidelity Advisor Sustainable Target Date 2050 Fund - Class M            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 3.50%          
Maximum Deferred Sales Charge (as a percentage) [129] 0.00%          
Management Fees (as a percentage of Assets) [130] 0.49%          
Distribution and Service (12b-1) Fees 0.50%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [130] 0.99%          
Expense Example, with Redemption, 1 Year $ 447          
Expense Example, with Redemption, 3 Years 654          
Expense Example, with Redemption, 5 Years 878          
Expense Example, with Redemption, 10 Years 1,521          
Expense Example, No Redemption, 1 Year 447          
Expense Example, No Redemption, 3 Years 654          
Expense Example, No Redemption, 5 Years 878          
Expense Example, No Redemption, 10 Years $ 1,521          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   16.26%       15.24% [132]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2050 Fund | Fidelity Advisor Sustainable Target Date 2050 Fund - Class C            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) [133] 1.00%          
Management Fees (as a percentage of Assets) [130] 0.49%          
Distribution and Service (12b-1) Fees 1.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [130] 1.49%          
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.          
Expense Example, with Redemption, 1 Year $ 252          
Expense Example, with Redemption, 3 Years 471          
Expense Example, with Redemption, 5 Years 813          
Expense Example, with Redemption, 10 Years 1,576          
Expense Example, No Redemption, 1 Year 152          
Expense Example, No Redemption, 3 Years 471          
Expense Example, No Redemption, 5 Years 813          
Expense Example, No Redemption, 10 Years $ 1,576          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   18.94%       16.24% [134]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2050 Fund | Fidelity Advisor Sustainable Target Date 2050 Fund - Class I            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [130] 0.49%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [130] 0.49%          
Expense Example, with Redemption, 1 Year $ 50          
Expense Example, with Redemption, 3 Years 157          
Expense Example, with Redemption, 5 Years 274          
Expense Example, with Redemption, 10 Years 616          
Expense Example, No Redemption, 1 Year 50          
Expense Example, No Redemption, 3 Years 157          
Expense Example, No Redemption, 5 Years 274          
Expense Example, No Redemption, 10 Years $ 616          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.18%       17.39% [135]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2050 Fund | Fidelity Advisor Sustainable Target Date 2050 Fund - Class Z            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [130] 0.39%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [130] 0.39%          
Expense Example, with Redemption, 1 Year $ 40          
Expense Example, with Redemption, 3 Years 125          
Expense Example, with Redemption, 5 Years 219          
Expense Example, with Redemption, 10 Years 493          
Expense Example, No Redemption, 1 Year 40          
Expense Example, No Redemption, 3 Years 125          
Expense Example, No Redemption, 5 Years 219          
Expense Example, No Redemption, 10 Years $ 493          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.29%       17.52% [136]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2050 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2050 Fund /Fidelity Advisor® Sustainable Target Date 2050 Fund A, M, C, I, Z            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2050 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus and in the sales charge waiver appendix to the prospectus.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Deferred Charges [Text Block] Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.          
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus          
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2050. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2050 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] institutional.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.57%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.78%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.54%)          
Performance Table Heading Average Annual Returns          
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2050 Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Target Date 2050 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   13.57%       14.20% [131]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2050 Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Target Date 2050 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   8.51%       11.33% [131]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2050 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2050 Fund | IXUGA            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2050 Composite Index℠        
Average Annual Return, Percent   20.98%       17.61%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2055 Fund | Fidelity Advisor Sustainable Target Date 2055 Fund - Class A            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 5.75%          
Maximum Deferred Sales Charge (as a percentage) [137] 0.00%          
Management Fees (as a percentage of Assets) [138] 0.49%          
Distribution and Service (12b-1) Fees 0.25%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [138] 0.74%          
Expense Example, with Redemption, 1 Year $ 646          
Expense Example, with Redemption, 3 Years 798          
Expense Example, with Redemption, 5 Years 963          
Expense Example, with Redemption, 10 Years 1,441          
Expense Example, No Redemption, 1 Year 646          
Expense Example, No Redemption, 3 Years 798          
Expense Example, No Redemption, 5 Years 963          
Expense Example, No Redemption, 10 Years $ 1,441          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   13.98%       14.54% [139]
Annual Return [Percent]     20.93% 12.70%    
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2055 Fund | Fidelity Advisor Sustainable Target Date 2055 Fund - Class M            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 3.50%          
Maximum Deferred Sales Charge (as a percentage) [137] 0.00%          
Management Fees (as a percentage of Assets) [138] 0.49%          
Distribution and Service (12b-1) Fees 0.50%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [138] 0.99%          
Expense Example, with Redemption, 1 Year $ 447          
Expense Example, with Redemption, 3 Years 654          
Expense Example, with Redemption, 5 Years 878          
Expense Example, with Redemption, 10 Years 1,521          
Expense Example, No Redemption, 1 Year 447          
Expense Example, No Redemption, 3 Years 654          
Expense Example, No Redemption, 5 Years 878          
Expense Example, No Redemption, 10 Years $ 1,521          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   16.33%       15.27% [140]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2055 Fund | Fidelity Advisor Sustainable Target Date 2055 Fund - Class C            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) [141] 1.00%          
Management Fees (as a percentage of Assets) [138] 0.49%          
Distribution and Service (12b-1) Fees 1.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [138] 1.49%          
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.          
Expense Example, with Redemption, 1 Year $ 252          
Expense Example, with Redemption, 3 Years 471          
Expense Example, with Redemption, 5 Years 813          
Expense Example, with Redemption, 10 Years 1,576          
Expense Example, No Redemption, 1 Year 152          
Expense Example, No Redemption, 3 Years 471          
Expense Example, No Redemption, 5 Years 813          
Expense Example, No Redemption, 10 Years $ 1,576          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   19.00%       16.24% [142]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2055 Fund | Fidelity Advisor Sustainable Target Date 2055 Fund - Class I            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [138] 0.49%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [138] 0.49%          
Expense Example, with Redemption, 1 Year $ 50          
Expense Example, with Redemption, 3 Years 157          
Expense Example, with Redemption, 5 Years 274          
Expense Example, with Redemption, 10 Years 616          
Expense Example, No Redemption, 1 Year 50          
Expense Example, No Redemption, 3 Years 157          
Expense Example, No Redemption, 5 Years 274          
Expense Example, No Redemption, 10 Years $ 616          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.21%       17.41% [143]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2055 Fund | Fidelity Advisor Sustainable Target Date 2055 Fund - Class Z            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [138] 0.39%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [138] 0.39%          
Expense Example, with Redemption, 1 Year $ 40          
Expense Example, with Redemption, 3 Years 125          
Expense Example, with Redemption, 5 Years 219          
Expense Example, with Redemption, 10 Years 493          
Expense Example, No Redemption, 1 Year 40          
Expense Example, No Redemption, 3 Years 125          
Expense Example, No Redemption, 5 Years 219          
Expense Example, No Redemption, 10 Years $ 493          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.32%       17.53% [144]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2055 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2055 Fund /Fidelity Advisor® Sustainable Target Date 2055 Fund A, M, C, I, Z            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2055 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus and in the sales charge waiver appendix to the prospectus.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 20 % of the average value of its portfolio.          
Portfolio Turnover, Rate 20.00%          
Expenses Deferred Charges [Text Block] Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.          
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus          
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2055. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2055 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] institutional.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.57%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.80%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.59%)          
Performance Table Heading Average Annual Returns          
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2055 Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Target Date 2055 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   13.59%       14.19% [139]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2055 Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Target Date 2055 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   8.55%       11.33% [139]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2055 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2055 Fund | IXUGF            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2055 Composite Index℠        
Average Annual Return, Percent   21.00%       17.61%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2060 Fund | Fidelity Advisor Sustainable Target Date 2060 Fund - Class A            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 5.75%          
Maximum Deferred Sales Charge (as a percentage) [145] 0.00%          
Management Fees (as a percentage of Assets) [146] 0.49%          
Distribution and Service (12b-1) Fees 0.25%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [146] 0.74%          
Expense Example, with Redemption, 1 Year $ 646          
Expense Example, with Redemption, 3 Years 798          
Expense Example, with Redemption, 5 Years 963          
Expense Example, with Redemption, 10 Years 1,441          
Expense Example, No Redemption, 1 Year 646          
Expense Example, No Redemption, 3 Years 798          
Expense Example, No Redemption, 5 Years 963          
Expense Example, No Redemption, 10 Years $ 1,441          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   13.92%       14.54% [147]
Annual Return [Percent]     20.87% 12.74%    
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2060 Fund | Fidelity Advisor Sustainable Target Date 2060 Fund - Class M            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 3.50%          
Maximum Deferred Sales Charge (as a percentage) [145] 0.00%          
Management Fees (as a percentage of Assets) [146] 0.49%          
Distribution and Service (12b-1) Fees 0.50%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [146] 0.99%          
Expense Example, with Redemption, 1 Year $ 447          
Expense Example, with Redemption, 3 Years 654          
Expense Example, with Redemption, 5 Years 878          
Expense Example, with Redemption, 10 Years 1,521          
Expense Example, No Redemption, 1 Year 447          
Expense Example, No Redemption, 3 Years 654          
Expense Example, No Redemption, 5 Years 878          
Expense Example, No Redemption, 10 Years $ 1,521          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   16.36%       15.28% [148]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2060 Fund | Fidelity Advisor Sustainable Target Date 2060 Fund - Class C            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) [149] 1.00%          
Management Fees (as a percentage of Assets) [146] 0.49%          
Distribution and Service (12b-1) Fees 1.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [146] 1.49%          
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.          
Expense Example, with Redemption, 1 Year $ 252          
Expense Example, with Redemption, 3 Years 471          
Expense Example, with Redemption, 5 Years 813          
Expense Example, with Redemption, 10 Years 1,576          
Expense Example, No Redemption, 1 Year 152          
Expense Example, No Redemption, 3 Years 471          
Expense Example, No Redemption, 5 Years 813          
Expense Example, No Redemption, 10 Years $ 1,576          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   19.01%       16.27% [150]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2060 Fund | Fidelity Advisor Sustainable Target Date 2060 Fund - Class I            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [146] 0.49%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [146] 0.49%          
Expense Example, with Redemption, 1 Year $ 50          
Expense Example, with Redemption, 3 Years 157          
Expense Example, with Redemption, 5 Years 274          
Expense Example, with Redemption, 10 Years 616          
Expense Example, No Redemption, 1 Year 50          
Expense Example, No Redemption, 3 Years 157          
Expense Example, No Redemption, 5 Years 274          
Expense Example, No Redemption, 10 Years $ 616          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.19%       17.42% [151]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2060 Fund | Fidelity Advisor Sustainable Target Date 2060 Fund - Class Z            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [146] 0.39%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [146] 0.39%          
Expense Example, with Redemption, 1 Year $ 40          
Expense Example, with Redemption, 3 Years 125          
Expense Example, with Redemption, 5 Years 219          
Expense Example, with Redemption, 10 Years 493          
Expense Example, No Redemption, 1 Year 40          
Expense Example, No Redemption, 3 Years 125          
Expense Example, No Redemption, 5 Years 219          
Expense Example, No Redemption, 10 Years $ 493          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.34%       17.54% [152]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2060 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2060 Fund /Fidelity Advisor® Sustainable Target Date 2060 Fund A, M, C, I, Z            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2060 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus and in the sales charge waiver appendix to the prospectus.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 26 % of the average value of its portfolio.          
Portfolio Turnover, Rate 26.00%          
Expenses Deferred Charges [Text Block] Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.          
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus          
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2060. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2060 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] institutional.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.57%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.86%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.56%)          
Performance Table Heading Average Annual Returns          
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2060 Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Target Date 2060 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   13.52%       14.18% [147]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2060 Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Target Date 2060 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   8.51%       11.33% [147]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2060 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2060 Fund | IXUGG            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2060 Composite Index℠        
Average Annual Return, Percent   21.00%       17.61%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2065 Fund | Fidelity Advisor Sustainable Target Date 2065 Fund - Class A            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 5.75%          
Maximum Deferred Sales Charge (as a percentage) [153] 0.00%          
Management Fees (as a percentage of Assets) [154] 0.49%          
Distribution and Service (12b-1) Fees 0.25%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [154] 0.74%          
Expense Example, with Redemption, 1 Year $ 646          
Expense Example, with Redemption, 3 Years 798          
Expense Example, with Redemption, 5 Years 963          
Expense Example, with Redemption, 10 Years 1,441          
Expense Example, No Redemption, 1 Year 646          
Expense Example, No Redemption, 3 Years 798          
Expense Example, No Redemption, 5 Years 963          
Expense Example, No Redemption, 10 Years $ 1,441          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   13.87%       14.52% [155]
Annual Return [Percent]     20.82% 12.74%    
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2065 Fund | Fidelity Advisor Sustainable Target Date 2065 Fund - Class M            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 3.50%          
Maximum Deferred Sales Charge (as a percentage) [153] 0.00%          
Management Fees (as a percentage of Assets) [154] 0.49%          
Distribution and Service (12b-1) Fees 0.50%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [154] 0.99%          
Expense Example, with Redemption, 1 Year $ 447          
Expense Example, with Redemption, 3 Years 654          
Expense Example, with Redemption, 5 Years 878          
Expense Example, with Redemption, 10 Years 1,521          
Expense Example, No Redemption, 1 Year 447          
Expense Example, No Redemption, 3 Years 654          
Expense Example, No Redemption, 5 Years 878          
Expense Example, No Redemption, 10 Years $ 1,521          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   16.40%       15.27% [156]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2065 Fund | Fidelity Advisor Sustainable Target Date 2065 Fund - Class C            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) [157] 1.00%          
Management Fees (as a percentage of Assets) [154] 0.49%          
Distribution and Service (12b-1) Fees 1.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [154] 1.49%          
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.          
Expense Example, with Redemption, 1 Year $ 252          
Expense Example, with Redemption, 3 Years 471          
Expense Example, with Redemption, 5 Years 813          
Expense Example, with Redemption, 10 Years 1,576          
Expense Example, No Redemption, 1 Year 152          
Expense Example, No Redemption, 3 Years 471          
Expense Example, No Redemption, 5 Years 813          
Expense Example, No Redemption, 10 Years $ 1,576          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   19.02%       16.25% [158]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2065 Fund | Fidelity Advisor Sustainable Target Date 2065 Fund - Class I            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [154] 0.49%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [154] 0.49%          
Expense Example, with Redemption, 1 Year $ 50          
Expense Example, with Redemption, 3 Years 157          
Expense Example, with Redemption, 5 Years 274          
Expense Example, with Redemption, 10 Years 616          
Expense Example, No Redemption, 1 Year 50          
Expense Example, No Redemption, 3 Years 157          
Expense Example, No Redemption, 5 Years 274          
Expense Example, No Redemption, 10 Years $ 616          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.23%       17.43% [159]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2065 Fund | Fidelity Advisor Sustainable Target Date 2065 Fund - Class Z            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [154] 0.39%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [154] 0.39%          
Expense Example, with Redemption, 1 Year $ 40          
Expense Example, with Redemption, 3 Years 125          
Expense Example, with Redemption, 5 Years 219          
Expense Example, with Redemption, 10 Years 493          
Expense Example, No Redemption, 1 Year 40          
Expense Example, No Redemption, 3 Years 125          
Expense Example, No Redemption, 5 Years 219          
Expense Example, No Redemption, 10 Years $ 493          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.28%       17.54% [160]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2065 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2065 Fund /Fidelity Advisor® Sustainable Target Date 2065 Fund A, M, C, I, Z            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2065 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus and in the sales charge waiver appendix to the prospectus.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 20 % of the average value of its portfolio.          
Portfolio Turnover, Rate 20.00%          
Expenses Deferred Charges [Text Block] Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.          
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus          
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2065. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2065 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] institutional.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.57%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.83%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.53%)          
Performance Table Heading Average Annual Returns          
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2065 Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Target Date 2065 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   13.53%       14.18% [155]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2065 Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Target Date 2065 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   8.49%       11.32% [155]
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2065 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2065 Fund | IXUGH            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2065 Composite Index℠        
Average Annual Return, Percent   21.00%       17.61%
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2070 Fund | Fidelity Advisor Sustainable Target Date 2070 Fund - Class A            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 5.75%          
Maximum Deferred Sales Charge (as a percentage) [161] 0.00%          
Management Fees (as a percentage of Assets) [162] 0.49%          
Distribution and Service (12b-1) Fees 0.25%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [162] 0.74%          
Expense Example, with Redemption, 1 Year $ 646          
Expense Example, with Redemption, 3 Years 798          
Expense Example, with Redemption, 5 Years 963          
Expense Example, with Redemption, 10 Years 1,441          
Expense Example, No Redemption, 1 Year 646          
Expense Example, No Redemption, 3 Years 798          
Expense Example, No Redemption, 5 Years 963          
Expense Example, No Redemption, 10 Years $ 1,441          
Annual Return, Inception Date Jun. 28, 2024          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   13.90%     11.41% [163]  
Annual Return [Percent]     20.85%      
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2070 Fund | Fidelity Advisor Sustainable Target Date 2070 Fund - Class M            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 3.50%          
Maximum Deferred Sales Charge (as a percentage) [161] 0.00%          
Management Fees (as a percentage of Assets) [162] 0.49%          
Distribution and Service (12b-1) Fees 0.50%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [162] 0.99%          
Expense Example, with Redemption, 1 Year $ 447          
Expense Example, with Redemption, 3 Years 654          
Expense Example, with Redemption, 5 Years 878          
Expense Example, with Redemption, 10 Years 1,521          
Expense Example, No Redemption, 1 Year 447          
Expense Example, No Redemption, 3 Years 654          
Expense Example, No Redemption, 5 Years 878          
Expense Example, No Redemption, 10 Years $ 1,521          
Annual Return, Inception Date Jun. 28, 2024          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   16.41%     12.95% [164]  
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2070 Fund | Fidelity Advisor Sustainable Target Date 2070 Fund - Class C            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) [165] 1.00%          
Management Fees (as a percentage of Assets) [162] 0.49%          
Distribution and Service (12b-1) Fees 1.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [162] 1.49%          
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.          
Expense Example, with Redemption, 1 Year $ 252          
Expense Example, with Redemption, 3 Years 471          
Expense Example, with Redemption, 5 Years 813          
Expense Example, with Redemption, 10 Years 1,576          
Expense Example, No Redemption, 1 Year 152          
Expense Example, No Redemption, 3 Years 471          
Expense Example, No Redemption, 5 Years 813          
Expense Example, No Redemption, 10 Years $ 1,576          
Annual Return, Inception Date Jun. 28, 2024          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   19.05%     15.09% [166]  
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2070 Fund | Fidelity Advisor Sustainable Target Date 2070 Fund - Class I            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [162] 0.49%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [162] 0.49%          
Expense Example, with Redemption, 1 Year $ 50          
Expense Example, with Redemption, 3 Years 157          
Expense Example, with Redemption, 5 Years 274          
Expense Example, with Redemption, 10 Years 616          
Expense Example, No Redemption, 1 Year 50          
Expense Example, No Redemption, 3 Years 157          
Expense Example, No Redemption, 5 Years 274          
Expense Example, No Redemption, 10 Years $ 616          
Annual Return, Inception Date Jun. 28, 2024          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.23%     16.24% [167]  
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2070 Fund | Fidelity Advisor Sustainable Target Date 2070 Fund - Class Z            
Prospectus Line Items            
Maximum Cumulative Sales Charge (as a percentage of Offering Price) 0.00%          
Maximum Deferred Sales Charge (as a percentage) 0.00%          
Management Fees (as a percentage of Assets) [162] 0.39%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [162] 0.39%          
Expense Example, with Redemption, 1 Year $ 40          
Expense Example, with Redemption, 3 Years 125          
Expense Example, with Redemption, 5 Years 219          
Expense Example, with Redemption, 10 Years 493          
Expense Example, No Redemption, 1 Year 40          
Expense Example, No Redemption, 3 Years 125          
Expense Example, No Redemption, 5 Years 219          
Expense Example, No Redemption, 10 Years $ 493          
Annual Return, Inception Date Jun. 28, 2024          
Average Annual Return, Label [Optional Text]   Return Before Taxes        
Average Annual Return, Percent   21.28%     16.31% [168]  
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2070 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2070 Fund /Fidelity Advisor® Sustainable Target Date 2070 Fund A, M, C, I, Z            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2070 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus and in the sales charge waiver appendix to the prospectus.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 19 % of the average value of its portfolio.          
Portfolio Turnover, Rate 19.00%          
Expenses Deferred Charges [Text Block] Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.          
Expense Breakpoint Discounts [Text] You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $ 50,000 in the fund or certain other Fidelity ® funds. More information about these and other discounts is available from your investment professional and in the "Fund Distribution" section beginning on page 118 of the prospectus          
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated and if you hold your shares:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2070. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2070 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the performance of the fund's shares over the past year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance. Visit institutional.fidelity.com for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the performance of the fund's shares over the past year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] institutional.fidelity.com          
Performance Past Does Not Indicate Future [Text] Past performance (before and after taxes) is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Bar Chart Narrative [Text Block] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Bar Chart Does Not Reflect Sales Loads [Text] The returns in the bar chart do not reflect any applicable sales charges; if sales charges were reflected, returns would be lower than those shown.          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.56%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.79%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Mar. 31, 2025          
Lowest Quarterly Return (0.69%)          
Performance Table Heading Average Annual Returns          
Performance Table Does Reflect Sales Loads Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges.          
Performance Table Uses Highest Federal Rate After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes.          
Performance Table Not Relevant to Tax Deferred The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan).          
Performance Table One Class of after Tax Shown [Text] After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary.          
Performance Table Explanation after Tax Higher Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
Performance Table Narrative Unlike the returns in the bar chart, the returns in the table reflect the maximum applicable sales charges. After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. After-tax returns for Class A are shown in the table below and after-tax returns for other classes will vary. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.          
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2070 Fund | After Taxes on Distributions | Fidelity Advisor Sustainable Target Date 2070 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions        
Average Annual Return, Percent   13.62%     10.98% [163]  
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2070 Fund | After Taxes on Distributions and Sales | Fidelity Advisor Sustainable Target Date 2070 Fund - Class A            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions and Sale of Fund Shares        
Average Annual Return, Percent   8.51%     8.74% [163]  
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2070 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%     17.78%  
FidelitySustainableTargetDateFunds-ComboClassAMCIZPro | Fidelity Sustainable Target Date 2070 Fund | IXTP0            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2070 Composite Index℠        
Average Annual Return, Percent   21.00%     17.21%  
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date Retirement Fund | Fidelity Sustainable Target Date Retirement Fund - Class K6            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [169] 0.21%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [169] 0.21%          
Expense Example, with Redemption, 1 Year $ 22          
Expense Example, with Redemption, 3 Years 68          
Expense Example, with Redemption, 5 Years 118          
Expense Example, with Redemption, 10 Years $ 268          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K6        
Average Annual Return, Percent   9.92%       6.78% [170]
Annual Return [Percent]     9.92% 4.16%    
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date Retirement Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date Retirement Fund /K6            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date Retirement Fund seeks high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 36 % of the average value of its portfolio.          
Portfolio Turnover, Rate 36.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a stable neutral asset allocation strategy. A revised neutral asset allocation strategy (approximately 18% in U.S. equity funds, 12% in international equity funds, 33% in U.S. investment grade bond funds, 5% in international bond funds, 2% in long-term treasury bond funds, 24% in short-term inflation protected bond funds, and 7% in short-term funds; allocations do not add to 100% due to rounding) is expected to take effect by the end of the first quarter of 2027. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.14%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Sep. 30, 2024          
Highest Quarterly Return 4.61%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.43%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date Retirement Fund | IXUFW            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date Retirement Composite Index℠        
Average Annual Return, Percent   9.31%       6.91%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date Retirement Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2010 Fund | Fidelity Sustainable Target Date 2010 Fund - Class K6            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [171] 0.21%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [171] 0.21%          
Expense Example, with Redemption, 1 Year $ 22          
Expense Example, with Redemption, 3 Years 68          
Expense Example, with Redemption, 5 Years 118          
Expense Example, with Redemption, 10 Years $ 268          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K6        
Average Annual Return, Percent   10.78%       7.77% [172]
Annual Return [Percent]     10.78% 5.02%    
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2010 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2010 Fund /K6            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2010 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 30 % of the average value of its portfolio.          
Portfolio Turnover, Rate 30.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2010. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who retired in or within a few years of 2010 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.18%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Sep. 30, 2024          
Highest Quarterly Return 4.90%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.51%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2010 Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2010 Fund | IXUFX            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2010 Composite Index℠        
Average Annual Return, Percent   10.22%       7.87%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2015 Fund | Fidelity Sustainable Target Date 2015 Fund - Class K6            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [173] 0.22%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [173] 0.22%          
Expense Example, with Redemption, 1 Year $ 23          
Expense Example, with Redemption, 3 Years 71          
Expense Example, with Redemption, 5 Years 124          
Expense Example, with Redemption, 10 Years $ 280          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K6        
Average Annual Return, Percent   12.37%       9.05% [174]
Annual Return [Percent]     12.37% 5.98%    
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2015 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2015 Fund /K6            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2015 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2015. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who retired in or within a few years of 2015 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.35%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Sep. 30, 2024          
Highest Quarterly Return 5.28%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.77%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2015 Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2015 Fund | IXUFY            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2015 Composite Index℠        
Average Annual Return, Percent   11.75%       9.11%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2020 Fund | Fidelity Sustainable Target Date 2020 Fund - Class K6            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [175] 0.23%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [175] 0.23%          
Expense Example, with Redemption, 1 Year $ 24          
Expense Example, with Redemption, 3 Years 74          
Expense Example, with Redemption, 5 Years 130          
Expense Example, with Redemption, 10 Years $ 293          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K6        
Average Annual Return, Percent   13.86%       10.30% [176]
Annual Return [Percent]     13.86% 6.92%    
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2020 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2020 Fund /K6            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2020 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 31 % of the average value of its portfolio.          
Portfolio Turnover, Rate 31.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2020. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who retired in or within a few years of 2020 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.50%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 5.86%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.98%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2020 Fund | LB001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Bloomberg U.S. Aggregate Bond Index        
Average Annual Return, Percent   7.30%       3.84%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2020 Fund | IXUFZ            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2020 Composite Index℠        
Average Annual Return, Percent   13.30%       10.36%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2025 Fund | Fidelity Sustainable Target Date 2025 Fund - Class K6            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [177] 0.24%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [177] 0.24%          
Expense Example, with Redemption, 1 Year $ 25          
Expense Example, with Redemption, 3 Years 77          
Expense Example, with Redemption, 5 Years 135          
Expense Example, with Redemption, 10 Years $ 306          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K6        
Average Annual Return, Percent   15.27%       11.42% [178]
Annual Return [Percent]     15.27% 7.62%    
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2025 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2025 Fund /K6            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2025 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 29 % of the average value of its portfolio.          
Portfolio Turnover, Rate 29.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2025. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2025 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.72%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 6.71%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (3.12%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2025 Fund | IXUG2            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2025 Composite Index℠        
Average Annual Return, Percent   14.75%       11.51%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2025 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2030 Fund | Fidelity Sustainable Target Date 2030 Fund - Class K6            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [179] 0.25%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [179] 0.25%          
Expense Example, with Redemption, 1 Year $ 26          
Expense Example, with Redemption, 3 Years 80          
Expense Example, with Redemption, 5 Years 141          
Expense Example, with Redemption, 10 Years $ 318          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K6        
Average Annual Return, Percent   16.22%       12.51% [180]
Annual Return [Percent]     16.22% 8.59%    
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2030 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2030 Fund /K6            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2030 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 43 % of the average value of its portfolio.          
Portfolio Turnover, Rate 43.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2030. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2030 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.78%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 7.45%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (3.04%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2030 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2030 Fund | IXUG3            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2030 Composite Index℠        
Average Annual Return, Percent   15.73%       12.60%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2035 Fund | Fidelity Sustainable Target Date 2035 Fund - Class K6            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [181] 0.27%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [181] 0.27%          
Expense Example, with Redemption, 1 Year $ 28          
Expense Example, with Redemption, 3 Years 87          
Expense Example, with Redemption, 5 Years 152          
Expense Example, with Redemption, 10 Years $ 343          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K6        
Average Annual Return, Percent   17.71%       14.32% [182]
Annual Return [Percent]     17.71% 10.18%    
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2035 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2035 Fund /K6            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2035 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 26 % of the average value of its portfolio.          
Portfolio Turnover, Rate 26.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2035. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2035 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (0.97%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 8.44%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.85%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2035 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2035 Fund | IXUG5            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2035 Composite Index℠        
Average Annual Return, Percent   17.08%       14.32%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2040 Fund | Fidelity Sustainable Target Date 2040 Fund - Class K6            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [183] 0.28%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [183] 0.28%          
Expense Example, with Redemption, 1 Year $ 29          
Expense Example, with Redemption, 3 Years 90          
Expense Example, with Redemption, 5 Years 157          
Expense Example, with Redemption, 10 Years $ 356          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K6        
Average Annual Return, Percent   20.09%       16.65% [184]
Annual Return [Percent]     20.09% 12.34%    
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2040 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2040 Fund /K6            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2040 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2040. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2040 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.18%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.17%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.59%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2040 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2040 Fund | IXUG8            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2040 Composite Index℠        
Average Annual Return, Percent   19.54%       16.61%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2045 Fund | Fidelity Sustainable Target Date 2045 Fund - Class K6            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [185] 0.29%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [185] 0.29%          
Expense Example, with Redemption, 1 Year $ 30          
Expense Example, with Redemption, 3 Years 93          
Expense Example, with Redemption, 5 Years 163          
Expense Example, with Redemption, 10 Years $ 368          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K6        
Average Annual Return, Percent   21.39%       17.64% [186]
Annual Return [Percent]     21.39% 13.15%    
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2045 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2045 Fund /K6            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2045 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2045. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2045 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.43%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.90%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.48%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2045 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2045 Fund | IXUG9            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2045 Composite Index℠        
Average Annual Return, Percent   20.97%       17.60%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2050 Fund | Fidelity Sustainable Target Date 2050 Fund - Class K6            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [187] 0.29%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [187] 0.29%          
Expense Example, with Redemption, 1 Year $ 30          
Expense Example, with Redemption, 3 Years 93          
Expense Example, with Redemption, 5 Years 163          
Expense Example, with Redemption, 10 Years $ 368          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K6        
Average Annual Return, Percent   21.35%       17.63% [188]
Annual Return [Percent]     21.35% 13.17%    
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2050 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2050 Fund /K6            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2050 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 27 % of the average value of its portfolio.          
Portfolio Turnover, Rate 27.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2050. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2050 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.43%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.92%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.45%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2050 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2050 Fund | IXUGA            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2050 Composite Index℠        
Average Annual Return, Percent   20.98%       17.61%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2055 Fund | Fidelity Sustainable Target Date 2055 Fund - Class K6            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [189] 0.29%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [189] 0.29%          
Expense Example, with Redemption, 1 Year $ 30          
Expense Example, with Redemption, 3 Years 93          
Expense Example, with Redemption, 5 Years 163          
Expense Example, with Redemption, 10 Years $ 368          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K6        
Average Annual Return, Percent   21.41%       17.65% [190]
Annual Return [Percent]     21.41% 13.18%    
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2055 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2055 Fund /K6            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2055 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 20 % of the average value of its portfolio.          
Portfolio Turnover, Rate 20.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2055. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2055 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.43%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.94%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.51%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2055 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2055 Fund | IXUGF            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2055 Composite Index℠        
Average Annual Return, Percent   21.00%       17.61%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2060 Fund | Fidelity Sustainable Target Date 2060 Fund - Class K6            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [191] 0.29%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [191] 0.29%          
Expense Example, with Redemption, 1 Year $ 30          
Expense Example, with Redemption, 3 Years 93          
Expense Example, with Redemption, 5 Years 163          
Expense Example, with Redemption, 10 Years $ 368          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K6        
Average Annual Return, Percent   21.43%       17.66% [192]
Annual Return [Percent]     21.43% 13.25%    
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2060 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2060 Fund /K6            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2060 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 26 % of the average value of its portfolio.          
Portfolio Turnover, Rate 26.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2060. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2060 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.50%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.91%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.48%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2060 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2060 Fund | IXUGG            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2060 Composite Index℠        
Average Annual Return, Percent   21.00%       17.61%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2065 Fund | Fidelity Sustainable Target Date 2065 Fund - Class K6            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [193] 0.29%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [193] 0.29%          
Expense Example, with Redemption, 1 Year $ 30          
Expense Example, with Redemption, 3 Years 93          
Expense Example, with Redemption, 5 Years 163          
Expense Example, with Redemption, 10 Years $ 368          
Annual Return, Inception Date May 11, 2023          
Average Annual Return, Label [Optional Text]   Class K6        
Average Annual Return, Percent   21.44%       17.65% [194]
Annual Return [Percent]     21.44% 13.11%    
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2065 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2065 Fund /K6            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2065 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 20 % of the average value of its portfolio.          
Portfolio Turnover, Rate 20.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2065. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2065 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.43%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.93%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Dec. 31, 2024          
Lowest Quarterly Return (2.48%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2065 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%       22.77%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2065 Fund | IXUGH            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2065 Composite Index℠        
Average Annual Return, Percent   21.00%       17.61%
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2070 Fund | Fidelity Sustainable Target Date 2070 Fund - Class K6            
Prospectus Line Items            
Management Fees (as a percentage of Assets) [195] 0.29%          
Distribution and Service (12b-1) Fees 0.00%          
Other Expenses (as a percentage of Assets): 0.00%          
Expenses (as a percentage of Assets) [195] 0.29%          
Expense Example, with Redemption, 1 Year $ 30          
Expense Example, with Redemption, 3 Years 93          
Expense Example, with Redemption, 5 Years 163          
Expense Example, with Redemption, 10 Years $ 368          
Annual Return, Inception Date Jun. 28, 2024          
Average Annual Return, Label [Optional Text]   Class K6        
Average Annual Return, Percent   21.40%     16.43% [196]  
Annual Return [Percent]     21.40%      
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2070 Fund            
Prospectus Line Items            
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity® Sustainable Target Date 2070 Fund /K6            
Objective [Heading] Investment Objective          
Objective, Primary [Text Block] Fidelity® Sustainable Target Date 2070 Fund seeks high total return until its target retirement date. Thereafter the fund's objective will be to seek high current income and, as a          
Objective, Secondary [Text Block] secondary objective, capital appreciation.          
Expense Heading [Optional Text] Fee Table          
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.          
Shareholder Fees Caption [Optional Text] Shareholder fees          
Shareholder Fee, Other $ 0          
Operating Expenses Caption [Optional Text] Annual Operating Expenses          
Portfolio Turnover [Heading] Portfolio Turnover          
Portfolio Turnover [Text Block] The fund will not incur transaction costs, such as commissions, when it buys and sells shares of underlying Fidelity ® funds (or "turns over" its portfolio), but it could incur transaction costs if it were to buy and sell other types of securities directly. If the fund were to buy and sell other types of securities directly, a higher portfolio turnover rate could indicate higher transaction costs and could result in higher taxes when fund shares are held in a taxable account. Such costs, if incurred, would not be reflected in annual operating expenses or in the example and would affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 19 % of the average value of its portfolio.          
Portfolio Turnover, Rate 19.00%          
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.          
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:          
Strategy [Heading] Principal Investment Strategies          
Strategy Narrative [Text Block] Investing at least 80% of assets in underlying funds that are (i) Fidelity® funds that invest in securities of issuers that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices or positive environmental, social and governance (ESG) characteristics (Fidelity® Sustainable Funds), (ii) Fidelity index funds that track an ESG Index (Fidelity® Sustainable Index Funds), and (iii) Fidelity® funds that do not have a principal ESG investment strategy but invest at least 80% of assets in U.S. and international sovereign or government-related debt securities that the Fidelity® Sustainable Target Date Fund Adviser believes have positive ESG characteristics (Fidelity® Traditional Funds) (collectively, underlying Fidelity® Funds). Derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives. Evaluating each security in which a Fidelity® Traditional Fund invests to determine whether 80% of assets are invested in sovereign or government-related debt securities whose issuers have positive ESG characteristics by considering the sustainability practices of the country or other issues based on an evaluation of such issuer's individual ESG profile using the Adviser's proprietary ESG rating process. The Adviser's proprietary ESG rating process evaluates an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and may also involve a qualitative assessment of an issuer's sustainability practices provided by the Adviser's research team. Allocating assets according to a neutral asset allocation strategy shown in the glide path below that adjusts over time until it reaches an allocation similar to that of the Fidelity® Sustainable Target Date Retirement Fund, approximately 15 to 20 years after the year 2070. The Adviser may modify the fund's neutral asset allocations from time to time when in the interests of shareholders. A revised neutral asset allocation strategy for the fund is expected to take effect by the end of the first quarter of 2027, as illustrated in the following chart. The Adviser has begun transitioning the neutral asset allocation percentages to achieve the desired allocations.     The neutral asset allocation shown in the glide path depicts the allocation to U.S. equity funds, international equity funds, bond funds (including U.S. investment grade bond, international bond, long-term inflation-protected bond, short-term inflation protected bond, and long-term treasury bond funds), and short-term funds. Buying and selling futures contracts (both long and short positions) in an effort to manage cash flows efficiently, remain fully invested, or facilitate asset allocation. The Adviser, under normal market conditions, will make investments that are consistent with seeking high total return for several years beyond the fund's target retirement date in an effort to achieve the fund's overall investment objective. The Adviser, under normal market conditions, will use an active asset allocation strategy to increase or decrease asset class exposures relative to the neutral asset allocations reflected above by up to 10% for equity funds, bond funds and short-term funds to reflect the Adviser's market outlook, which is primarily focused on the intermediate term. The asset allocations in the glide path above are referred to as neutral because they do not reflect any decisions made by the Adviser to overweight or underweight an asset class. The Adviser may also make active asset allocations within other asset classes (such as commodities, high yield debt (also referred to as junk bonds), floating rate debt, real estate debt, and emerging markets debt) from 0% to 10% of the fund's total assets individually, but no more than 25% in aggregate within those other asset classes. Such asset classes are not reflected in the neutral asset allocations reflected in the glide path above. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Designed for investors who anticipate retiring in or within a few years of 2070 (target retirement date) at or around age 65. Fidelity® Sustainable Funds employ sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Description of Underlying Fidelity® Funds" for additional information. When the neutral asset allocation of a fund matches Fidelity ® Sustainable Target Date Retirement Fund's neutral asset allocation (approximately 15 to 20 years after the year indicated in the fund's name), the Board of Trustees may combine the fund with Fidelity ® Sustainable Target Date Retirement Fund, without shareholder approval, and the fund's shareholders will become shareholders of Fidelity ® Sustainable Target Date Retirement Fund.          
Bar Chart and Performance Table [Heading] Performance          
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the performance of the fund's shares over the past year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time. The hypothetical composite of market indexes has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance is not an indication of future performance. Visit www.401k.com and log in for more recent performance information.          
Performance Information Illustrates Variability of Returns [Text] The information illustrates the performance of the fund's shares over the past year and compares the performance of the fund's shares to the performance of a securities market index and a hypothetical composite of market indexes over various periods of time.          
Performance Availability Website Address [Text] www.401k.com          
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.          
Bar Chart [Heading] Year-by-Year Returns          
Year to Date Return, Label [Optional Text]    Year-to-Date Return          
Bar Chart, Year to Date Return, Date Mar. 31, 2026          
Bar Chart, Year to Date Return (1.40%)          
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return          
Highest Quarterly Return, Date Jun. 30, 2025          
Highest Quarterly Return 10.98%          
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return          
Lowest Quarterly Return, Date Mar. 31, 2025          
Lowest Quarterly Return (0.59%)          
Performance Table Heading Average Annual Returns          
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2070 Fund | SP001            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   S&P 500® Index        
Average Annual Return, Percent   17.88%     17.78%  
FidelitySustainableTargetDateFunds-ComboClassK6Pro | Fidelity Sustainable Target Date 2070 Fund | IXTP0            
Prospectus Line Items            
Average Annual Return, Label [Optional Text]   Fidelity Sustainable Target Date 2070 Composite Index℠        
Average Annual Return, Percent   21.00%     17.21%  
Document Type 485BPOS          
Registrant Name Fidelity Aberdeen Street Trust          
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[27]
A Adjusted to reflect current fees.
[28]
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A Adjusted to reflect current fees.
[30]
A From May 11, 2023 .
[31]
A Adjusted to reflect current fees.
[32]
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[40]
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[41]
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[42]
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[44]
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[45]
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[48]
A From May 11, 2023 .
[49]
A Adjusted to reflect current fees.
[50]
A From May 11, 2023 .
[51]
A Adjusted to reflect current fees.
[52]
A From May 11, 2023 .
[53]
A Adjusted to reflect current fees.
[54]
A From May 11, 2023 .
[55]
A Adjusted to reflect current fees.
[56]
A From June 28, 2024 .
[57]
A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.
[58]
A Adjusted to reflect current fees.
[59]
A From May 11, 2023 .
[60]
B From May 11, 2023 .
[61]
B On Class C shares redeemed less than one year after purchase.
[62]
C From May 11, 2023 .
[63]
D From May 11, 2023 .
[64]
E From May 11, 2023 .
[65]
A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.
[66]
A Adjusted to reflect current fees.
[67]
A From May 11, 2023 .
[68]
B From May 11, 2023 .
[69]
B On Class C shares redeemed less than one year after purchase.
[70]
C From May 11, 2023 .
[71]
D From May 11, 2023 .
[72]
E From May 11, 2023 .
[73]
A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.
[74]
A Adjusted to reflect current fees.
[75]
A From May 11, 2023 .
[76]
B From May 11, 2023 .
[77]
B On Class C shares redeemed less than one year after purchase.
[78]
C From May 11, 2023 .
[79]
D From May 11, 2023 .
[80]
E From May 11, 2023 .
[81]
A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.
[82]
A Adjusted to reflect current fees.
[83]
A From May 11, 2023 .
[84]
B From May 11, 2023 .
[85]
B On Class C shares redeemed less than one year after purchase.
[86]
C From May 11, 2023 .
[87]
D From May 11, 2023 .
[88]
E From May 11, 2023 .
[89]
A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.
[90]
A Adjusted to reflect current fees.
[91]
A From May 11, 2023 .
[92]
B From May 11, 2023 .
[93]
B On Class C shares redeemed less than one year after purchase.
[94]
C From May 11, 2023 .
[95]
D From May 11, 2023 .
[96]
E From May 11, 2023 .
[97]
A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.
[98]
A Adjusted to reflect current fees.
[99]
A From May 11, 2023 .
[100]
B From May 11, 2023 .
[101]
B On Class C shares redeemed less than one year after purchase.
[102]
C From May 11, 2023 .
[103]
D From May 11, 2023 .
[104]
E From May 11, 2023 .
[105]
A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.
[106]
A Adjusted to reflect current fees.
[107]
A From May 11, 2023 .
[108]
B From May 11, 2023 .
[109]
B On Class C shares redeemed less than one year after purchase.
[110]
C From May 11, 2023 .
[111]
D From May 11, 2023 .
[112]
E From May 11, 2023 .
[113]
A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.
[114]
A Adjusted to reflect current fees.
[115]
A From May 11, 2023 .
[116]
B From May 11, 2023 .
[117]
B On Class C shares redeemed less than one year after purchase.
[118]
C From May 11, 2023 .
[119]
D From May 11, 2023 .
[120]
E From May 11, 2023 .
[121]
A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.
[122]
A Adjusted to reflect current fees.
[123]
A From May 11, 2023 .
[124]
B From May 11, 2023 .
[125]
B On Class C shares redeemed less than one year after purchase.
[126]
C From May 11, 2023 .
[127]
D From May 11, 2023 .
[128]
E From May 11, 2023 .
[129]
A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.
[130]
A Adjusted to reflect current fees.
[131]
A From May 11, 2023 .
[132]
B From May 11, 2023 .
[133]
B On Class C shares redeemed less than one year after purchase.
[134]
C From May 11, 2023 .
[135]
D From May 11, 2023 .
[136]
E From May 11, 2023 .
[137]
A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.
[138]
A Adjusted to reflect current fees.
[139]
A From May 11, 2023 .
[140]
B From May 11, 2023 .
[141]
B On Class C shares redeemed less than one year after purchase.
[142]
C From May 11, 2023 .
[143]
D From May 11, 2023 .
[144]
E From May 11, 2023 .
[145]
A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.
[146]
A Adjusted to reflect current fees.
[147]
A From May 11, 2023 .
[148]
B From May 11, 2023 .
[149]
B On Class C shares redeemed less than one year after purchase.
[150]
C From May 11, 2023 .
[151]
D From May 11, 2023 .
[152]
E From May 11, 2023 .
[153]
A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.
[154]
A Adjusted to reflect current fees.
[155]
A From May 11, 2023 .
[156]
B From May 11, 2023 .
[157]
B On Class C shares redeemed less than one year after purchase.
[158]
C From May 11, 2023 .
[159]
D From May 11, 2023 .
[160]
E From May 11, 2023 .
[161]
A Class A and Class M purchases of $1 million or more will not be subject to a front-end sales charge. Such Class A and Class M purchases may be subject, upon redemption, to a contingent deferred sales charge (CDSC) of 1.00% and 0.25%, respectively.
[162]
A Adjusted to reflect current fees.
[163]
A From June 28, 2024 .
[164]
B From June 28, 2024 .
[165]
B On Class C shares redeemed less than one year after purchase.
[166]
C From June 28, 2024 .
[167]
D From June 28, 2024 .
[168]
E From June 28, 2024 .
[169]
A Adjusted to reflect current fees.
[170]
A From May 11, 2023 .
[171]
A Adjusted to reflect current fees.
[172]
A From May 11, 2023 .
[173]
A Adjusted to reflect current fees.
[174]
A From May 11, 2023 .
[175]
A Adjusted to reflect current fees.
[176]
A From May 11, 2023 .
[177]
A Adjusted to reflect current fees.
[178]
A From May 11, 2023 .
[179]
A Adjusted to reflect current fees.
[180]
A From May 11, 2023 .
[181]
A Adjusted to reflect current fees.
[182]
A From May 11, 2023 .
[183]
A Adjusted to reflect current fees.
[184]
A From May 11, 2023 .
[185]
A Adjusted to reflect current fees.
[186]
A From May 11, 2023 .
[187]
A Adjusted to reflect current fees.
[188]
A From May 11, 2023 .
[189]
A Adjusted to reflect current fees.
[190]
A From May 11, 2023 .
[191]
A Adjusted to reflect current fees.
[192]
A From May 11, 2023 .
[193]
A Adjusted to reflect current fees.
[194]
A From May 11, 2023 .
[195]
A Adjusted to reflect current fees.
[196]
A From June 28, 2024 .