v3.25.2
Risk/Return Detail Data - FidelityAdvisorRealEstateFund-AMCIZPRO - USD ($)
 12 Months Ended 60 Months Ended 84 Months Ended 120 Months Ended
Sep. 29, 2025
Sep. 29, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Sep. 29, 2025
Sep. 29, 2025
Sep. 29, 2025
FidelityAdvisorRealEstateFund-AMCIZPRO | Fidelity Advisor Real Estate Fund | Fidelity Advisor Real Estate 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) [1] 0.00%                            
Management Fees (as a percentage of Assets) 0.72%                            
Distribution and Service (12b-1) Fees 0.25%                            
Other Expenses (as a percentage of Assets): 0.07%                            
Expenses (as a percentage of Assets) 1.04%                            
Expense Example, with Redemption, 1 Year $ 675                            
Expense Example, with Redemption, 3 Years 887                            
Expense Example, with Redemption, 5 Years 1,116                            
Expense Example, with Redemption, 10 Years 1,773                            
Expense Example, No Redemption, 1 Year 675                            
Expense Example, No Redemption, 3 Years 887                            
Expense Example, No Redemption, 5 Years 1,116                            
Expense Example, No Redemption, 10 Years $ 1,773                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   (0.07%)                     0.53%   2.85%
Annual Return [Percent]     6.03% 10.79% (28.09%) 38.51% (6.90%) 22.72% (6.66%) 3.58% 5.26% 3.29%      
FidelityAdvisorRealEstateFund-AMCIZPRO | Fidelity Advisor Real Estate Fund | Fidelity Advisor Real Estate 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) [1] 0.00%                            
Management Fees (as a percentage of Assets) 0.72%                            
Distribution and Service (12b-1) Fees 0.50%                            
Other Expenses (as a percentage of Assets): 0.07%                            
Expenses (as a percentage of Assets) 1.29%                            
Expense Example, with Redemption, 1 Year $ 477                            
Expense Example, with Redemption, 3 Years 745                            
Expense Example, with Redemption, 5 Years 1,033                            
Expense Example, with Redemption, 10 Years 1,852                            
Expense Example, No Redemption, 1 Year 477                            
Expense Example, No Redemption, 3 Years 745                            
Expense Example, No Redemption, 5 Years 1,033                            
Expense Example, No Redemption, 10 Years $ 1,852                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   2.15%                     0.79%   2.87%
FidelityAdvisorRealEstateFund-AMCIZPRO | Fidelity Advisor Real Estate Fund | Fidelity Advisor Real Estate 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) [2] 1.00%                            
Management Fees (as a percentage of Assets) 0.72%                            
Distribution and Service (12b-1) Fees 1.00%                            
Other Expenses (as a percentage of Assets): 0.07%                            
Expenses (as a percentage of Assets) 1.79%                            
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.                            
Expense Example, with Redemption, 1 Year $ 282                            
Expense Example, with Redemption, 3 Years 563                            
Expense Example, with Redemption, 5 Years 970                            
Expense Example, with Redemption, 10 Years 1,908                            
Expense Example, No Redemption, 1 Year 182                            
Expense Example, No Redemption, 3 Years 563                            
Expense Example, No Redemption, 5 Years 970                            
Expense Example, No Redemption, 10 Years $ 1,908                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   4.28%                     0.95%   2.81%
FidelityAdvisorRealEstateFund-AMCIZPRO | Fidelity Advisor Real Estate Fund | Fidelity Advisor Real Estate 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) 0.71%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.07%                            
Expenses (as a percentage of Assets) 0.78%                            
Expense Example, with Redemption, 1 Year $ 80                            
Expense Example, with Redemption, 3 Years 249                            
Expense Example, with Redemption, 5 Years 433                            
Expense Example, with Redemption, 10 Years 966                            
Expense Example, No Redemption, 1 Year 80                            
Expense Example, No Redemption, 3 Years 249                            
Expense Example, No Redemption, 5 Years 433                            
Expense Example, No Redemption, 10 Years $ 966                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   6.30%                     1.98%   3.73%
FidelityAdvisorRealEstateFund-AMCIZPRO | Fidelity Advisor Real Estate Fund | Fidelity Advisor Real Estate 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) 0.56%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.07%                            
Expenses (as a percentage of Assets) 0.63%                            
Expense Example, with Redemption, 1 Year $ 64                            
Expense Example, with Redemption, 3 Years 202                            
Expense Example, with Redemption, 5 Years 351                            
Expense Example, with Redemption, 10 Years 786                            
Expense Example, No Redemption, 1 Year 64                            
Expense Example, No Redemption, 3 Years 202                            
Expense Example, No Redemption, 5 Years 351                            
Expense Example, No Redemption, 10 Years $ 786                            
Annual Return, Inception Date Oct. 02, 2018                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   6.49%                     2.19% 3.99% [3]  
FidelityAdvisorRealEstateFund-AMCIZPRO | Fidelity Advisor Real Estate Fund                              
Prospectus Line Items                              
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity Advisor® Real Estate Fund /A, M, C, I, Z                              
Objective [Heading] Investment Objective                            
Objective, Primary [Text Block] Fidelity Advisor® Real Estate Fund seeks above-average income and long-term capital growth, consistent with reasonable investment risk. The fund seeks to provide a yield that exceeds the composite yield of the S&P 500 ® Index.                            
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 32 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 pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 72 % of the average value of its portfolio.                            
Portfolio Turnover, Rate 72.00%                            
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 32 of the prospectus                            
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000                            
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] Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in the real estate industry and other real estate related investments. A real estate entity or real estate related investment is any company that is principally engaged in the real estate industry and includes commercial and residential mortgage-backed securities; debt securities of real estate entities; equity securities of entities whose primary assets are mortgage loans or commercial or residential mortgage-backed securities; REITs that either own properties or make construction loans and preferred stocks of REITs; real estate developers; companies with substantial real estate holdings; and other companies whose products and services are related to the real estate industry, such as building supply manufacturers, mortgage lenders, or mortgage servicing companies. The Adviser considers a company to be principally engaged in the real estate industry if (i) at least 50% of its assets, income, sales or profits are committed to, or derived from, the real estate industry, or (ii) a third party has given the company an industry or sector classification consistent with the real estate industry. Effective December 11, 2025, 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.   Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.                            
Strategy Portfolio Concentration [Text] Normally investing at least 80% of assets in securities of companies principally engaged in the real estate industry and other real estate related investments.                            
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 an additional index over various periods of time. The additional index 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 an additional index 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 Jun. 30, 2025                            
Bar Chart, Year to Date Return 1.45%                            
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                            
Highest Quarterly Return, Date Dec. 31, 2023                            
Highest Quarterly Return 17.88%                            
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                            
Lowest Quarterly Return, Date Mar. 31, 2020                            
Lowest Quarterly Return (23.06%)                            
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.                            
FidelityAdvisorRealEstateFund-AMCIZPRO | Fidelity Advisor Real Estate Fund | After Taxes on Distributions | Fidelity Advisor Real Estate Fund - Class A                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                          
Average Annual Return, Percent   (2.04%)                     (1.29%)   1.06%
FidelityAdvisorRealEstateFund-AMCIZPRO | Fidelity Advisor Real Estate Fund | After Taxes on Distributions and Sales | Fidelity Advisor Real Estate 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   1.14%                     0.19%   1.89%
FidelityAdvisorRealEstateFund-AMCIZPRO | Fidelity Advisor Real Estate Fund | IXWEJ                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   MSCI US IMI Real Estate 25/50 Linked Index                          
Average Annual Return, Percent   5.05%                     0.97%   3.65%
FidelityAdvisorRealEstateFund-AMCIZPRO | Fidelity Advisor Real Estate Fund | SP001                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   S&P 500® Index                          
Average Annual Return, Percent   25.02%                     14.53%   13.10%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | Fidelity Advisor Biotechnology 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) [4] 0.00%                            
Management Fees (as a percentage of Assets) 0.69%                            
Distribution and Service (12b-1) Fees 0.25%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 0.96%                            
Expense Example, with Redemption, 1 Year $ 667                            
Expense Example, with Redemption, 3 Years 863                            
Expense Example, with Redemption, 5 Years 1,075                            
Expense Example, with Redemption, 10 Years 1,685                            
Expense Example, No Redemption, 1 Year 667                            
Expense Example, No Redemption, 3 Years 863                            
Expense Example, No Redemption, 5 Years 1,075                            
Expense Example, No Redemption, 10 Years $ 1,685                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   (0.71%)                     5.21%   5.23%
Annual Return [Percent]     5.34% 10.68% (7.95%) (3.56%) 32.16% 25.70% (3.78%) 25.80% (23.58%) 11.07%      
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | Fidelity Advisor Biotechnology 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) [4] 0.00%                            
Management Fees (as a percentage of Assets) 0.69%                            
Distribution and Service (12b-1) Fees 0.50%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 1.21%                            
Expense Example, with Redemption, 1 Year $ 469                            
Expense Example, with Redemption, 3 Years 721                            
Expense Example, with Redemption, 5 Years 992                            
Expense Example, with Redemption, 10 Years 1,765                            
Expense Example, No Redemption, 1 Year 469                            
Expense Example, No Redemption, 3 Years 721                            
Expense Example, No Redemption, 5 Years 992                            
Expense Example, No Redemption, 10 Years $ 1,765                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   1.38%                     5.42%   5.17%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | Fidelity Advisor Biotechnology 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) [5] 1.00%                            
Management Fees (as a percentage of Assets) 0.69%                            
Distribution and Service (12b-1) Fees 1.00%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 1.71%                            
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.                            
Expense Example, with Redemption, 1 Year $ 274                            
Expense Example, with Redemption, 3 Years 539                            
Expense Example, with Redemption, 5 Years 928                            
Expense Example, with Redemption, 10 Years 1,821                            
Expense Example, No Redemption, 1 Year 174                            
Expense Example, No Redemption, 3 Years 539                            
Expense Example, No Redemption, 5 Years 928                            
Expense Example, No Redemption, 10 Years $ 1,821                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   3.55%                     5.66%   5.22%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | Fidelity Advisor Biotechnology 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) 0.69%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 0.71%                            
Expense Example, with Redemption, 1 Year $ 73                            
Expense Example, with Redemption, 3 Years 227                            
Expense Example, with Redemption, 5 Years 395                            
Expense Example, with Redemption, 10 Years 883                            
Expense Example, No Redemption, 1 Year 73                            
Expense Example, No Redemption, 3 Years 227                            
Expense Example, No Redemption, 5 Years 395                            
Expense Example, No Redemption, 10 Years $ 883                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   5.61%                     6.75%   6.13%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | Fidelity Advisor Biotechnology 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) 0.56%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 0.58%                            
Expense Example, with Redemption, 1 Year $ 59                            
Expense Example, with Redemption, 3 Years 186                            
Expense Example, with Redemption, 5 Years 324                            
Expense Example, with Redemption, 10 Years 726                            
Expense Example, No Redemption, 1 Year 59                            
Expense Example, No Redemption, 3 Years 186                            
Expense Example, No Redemption, 5 Years 324                            
Expense Example, No Redemption, 10 Years $ 726                            
Annual Return, Inception Date Oct. 02, 2018                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   5.73%                     6.89% 6.70% [6]  
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund                              
Prospectus Line Items                              
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity Advisor® Biotechnology Fund /A, M, C, I, Z                              
Objective [Heading] Investment Objective                            
Objective, Primary [Text Block] Fidelity Advisor® Biotechnology Fund seeks 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 59 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 pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 51 % of the average value of its portfolio.                            
Portfolio Turnover, Rate 51.00%                            
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 59 of the prospectus                            
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000                            
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] Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in the research, development, manufacture, and distribution of various biotechnological products, services, and processes, and companies that benefit significantly from scientific and technological advances in biotechnology. These companies may include, for example, companies engaged in the research, development, manufacturing, or marketing of products based in whole or in part on genetic analysis and genetic engineering. Fidelity may consider a company to be principally engaged in the designated business activity or activities based on: (i) the level of a company's assets, income, sales, or profits that are committed to, derived from, or related to the designated business activity or activities, or (ii) whether a third party has given the company an industry or sector classification consistent with the designated business activity or activities. Whether a company is principally engaged in the designated business activity or activities can be determined under any of these factors. Effective December 11, 2025, 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.   Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.                            
Strategy Portfolio Concentration [Text] Normally investing at least 80% of assets in securities of companies principally engaged in the research, development, manufacture, and distribution of various biotechnological products, services, and processes, and companies that benefit significantly from scientific and technological advances in biotechnology.                            
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 an additional index over various periods of time. The additional index 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 an additional index 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 Jun. 30, 2025                            
Bar Chart, Year to Date Return (4.01%)                            
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                            
Highest Quarterly Return, Date Jun. 30, 2020                            
Highest Quarterly Return 30.29%                            
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                            
Lowest Quarterly Return, Date Mar. 31, 2016                            
Lowest Quarterly Return (27.76%)                            
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.                            
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | After Taxes on Distributions | Fidelity Advisor Biotechnology Fund - Class A                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                          
Average Annual Return, Percent   (2.30%)                     3.25%   3.89%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | After Taxes on Distributions and Sales | Fidelity Advisor Biotechnology 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   0.27%                     3.63%   3.85%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | SP001                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   S&P 500® Index                          
Average Annual Return, Percent   25.02%                     14.53%   13.10%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Biotechnology Fund | F1501                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   MSCI U.S. IMI Biotechnology 25-50 Index                          
Average Annual Return, Percent   3.49%                     7.83%   7.08%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Consumer Discretionary Fund | Fidelity Advisor Consumer Discretionary 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) [7] 0.00%                            
Management Fees (as a percentage of Assets) 0.70%                            
Distribution and Service (12b-1) Fees 0.25%                            
Other Expenses (as a percentage of Assets): 0.04%                            
Expenses (as a percentage of Assets) 0.99%                            
Expense Example, with Redemption, 1 Year $ 670                            
Expense Example, with Redemption, 3 Years 872                            
Expense Example, with Redemption, 5 Years 1,091                            
Expense Example, with Redemption, 10 Years 1,718                            
Expense Example, No Redemption, 1 Year 670                            
Expense Example, No Redemption, 3 Years 872                            
Expense Example, No Redemption, 5 Years 1,091                            
Expense Example, No Redemption, 10 Years $ 1,718                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   17.26%                     11.73%   11.10%
Annual Return [Percent]     24.41% 41.58% (35.18%) 18.87% 36.14% 26.64% (1.36%) 21.77% 4.14% 3.83%      
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Consumer Discretionary Fund | Fidelity Advisor Consumer Discretionary 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) [7] 0.00%                            
Management Fees (as a percentage of Assets) 0.72%                            
Distribution and Service (12b-1) Fees 0.50%                            
Other Expenses (as a percentage of Assets): 0.03%                            
Expenses (as a percentage of Assets) 1.25%                            
Expense Example, with Redemption, 1 Year $ 473                            
Expense Example, with Redemption, 3 Years 733                            
Expense Example, with Redemption, 5 Years 1,012                            
Expense Example, with Redemption, 10 Years 1,808                            
Expense Example, No Redemption, 1 Year 473                            
Expense Example, No Redemption, 3 Years 733                            
Expense Example, No Redemption, 5 Years 1,012                            
Expense Example, No Redemption, 10 Years $ 1,808                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   19.71%                     11.96%   11.06%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Consumer Discretionary Fund | Fidelity Advisor Consumer Discretionary 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) [8] 1.00%                            
Management Fees (as a percentage of Assets) 0.71%                            
Distribution and Service (12b-1) Fees 1.00%                            
Other Expenses (as a percentage of Assets): 0.04%                            
Expenses (as a percentage of Assets) 1.75%                            
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.                            
Expense Example, with Redemption, 1 Year $ 278                            
Expense Example, with Redemption, 3 Years 551                            
Expense Example, with Redemption, 5 Years 949                            
Expense Example, with Redemption, 10 Years 1,862                            
Expense Example, No Redemption, 1 Year 178                            
Expense Example, No Redemption, 3 Years 551                            
Expense Example, No Redemption, 5 Years 949                            
Expense Example, No Redemption, 10 Years $ 1,862                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   22.45%                     12.22%   11.09%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Consumer Discretionary Fund | Fidelity Advisor Consumer Discretionary 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) 0.69%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.04%                            
Expenses (as a percentage of Assets) 0.73%                            
Expense Example, with Redemption, 1 Year $ 75                            
Expense Example, with Redemption, 3 Years 233                            
Expense Example, with Redemption, 5 Years 406                            
Expense Example, with Redemption, 10 Years 906                            
Expense Example, No Redemption, 1 Year 75                            
Expense Example, No Redemption, 3 Years 233                            
Expense Example, No Redemption, 5 Years 406                            
Expense Example, No Redemption, 10 Years $ 906                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   24.70%                     13.37%   12.06%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Consumer Discretionary Fund | Fidelity Advisor Consumer Discretionary 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) 0.56%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.04%                            
Expenses (as a percentage of Assets) 0.60%                            
Expense Example, with Redemption, 1 Year $ 61                            
Expense Example, with Redemption, 3 Years 192                            
Expense Example, with Redemption, 5 Years 335                            
Expense Example, with Redemption, 10 Years 750                            
Expense Example, No Redemption, 1 Year 61                            
Expense Example, No Redemption, 3 Years 192                            
Expense Example, No Redemption, 5 Years 335                            
Expense Example, No Redemption, 10 Years $ 750                            
Annual Return, Inception Date Oct. 02, 2018                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   24.85%                     13.51% 12.11% [9]  
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Consumer Discretionary Fund                              
Prospectus Line Items                              
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity Advisor® Consumer Discretionary Fund /A, M, C, I, Z                              
Objective [Heading] Investment Objective                            
Objective, Primary [Text Block] Fidelity Advisor® Consumer Discretionary Fund seeks 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 59 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 pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, 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 59 of the prospectus                            
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000                            
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] Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in the manufacture and distribution of consumer discretionary products and services. Consumer discretionary products and services are non-essential products and services whose demand tends to increase as consumers' disposable income increases, such as automobiles, apparel, electronics, home furnishings, and travel and leisure products and services. These companies may include, for example, on-line retailers; department stores and specialty retailers including apparel, electronics, automotive, and home furnishing stores; manufacturers of auto parts and accessories, tire and rubber, autos, motorcycles, and scooters; manufacturers of consumer electronic products, including TVs and home audio equipment; manufacturers of household appliances and home furnishings; residential construction companies; manufacturers of leisure products; manufacturers of apparel, accessories, footwear, textiles, and luxury goods; gaming facility, hotel, cruise and travel agency owners and operators; restaurants and caterers; and companies providing educational, home security, legal, and personal services. Fidelity may consider a company to be principally engaged in the designated business activity or activities based on: (i) the level of a company's assets, income, sales, or profits that are committed to, derived from, or related to the designated business activity or activities, or (ii) whether a third party has given the company an industry or sector classification consistent with the designated business activity or activities. Whether a company is principally engaged in the designated business activity or activities can be determined under any of these factors. Effective December 11, 2025, 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.   Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments. Proposed Reorganization. The Board of Trustees of Fidelity Advisor Series VII has unanimously approved an Agreement and Plan of Reorganization ("Agreement") between Fidelity Advisor ® Consumer Discretionary Fund and Consumer Discretionary Portfolio pursuant to which Fidelity Advisor ® Consumer Discretionary Fund would be reorganized on a tax-free basis with and into Consumer Discretionary Portfolio. As a result of the proposed Reorganization, shareholders of Fidelity Advisor ® Consumer Discretionary Fund would receive, respectively, corresponding shares of Consumer Discretionary Portfolio. The Agreement provides for the transfer of all of the assets of Fidelity Advisor ® Consumer Discretionary Fund in exchange for corresponding shares of Consumer Discretionary Portfolio equal in value to the net assets of Fidelity Advisor ® Consumer Discretionary Fund and the assumption by Consumer Discretionary Portfolio of all of the liabilities of Fidelity Advisor ® Consumer Discretionary Fund. After the exchange, Fidelity Advisor ® Consumer Discretionary Fund will distribute the Consumer Discretionary Portfolio shares to its shareholders pro rata, in liquidation of Fidelity Advisor ® Consumer Discretionary Fund. As a result, shareholders of Fidelity Advisor ® Consumer Discretionary Fund will become shareholders of Consumer Discretionary Portfolio (these transactions are collectively referred to as the "Reorganization"). The Reorganization, which does not require shareholder approval, is expected to take place on or about November 14, 2025. The Reorganization is expected to be a tax-free transaction. This means that neither Fidelity Advisor ® Consumer Discretionary Fund nor its shareholders will recognize any gain or loss as a direct result of the Reorganization. Effective after the close of business on the business day prior to the Reorganization, new positions in the fund may no longer be opened. Existing shareholders may continue to hold their shares and purchase additional shares through the reinvestment of dividend and capital gain distributions until the fund's Reorganization takes place. For more detailed information, please call Fidelity at 1-877-208-0098.                            
Strategy Portfolio Concentration [Text] Normally investing at least 80% of assets in securities of companies principally engaged in the manufacture and distribution of consumer discretionary products and services.                            
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 an additional index over various periods of time. The additional index 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 an additional index 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 Jun. 30, 2025                            
Bar Chart, Year to Date Return (4.52%)                            
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                            
Highest Quarterly Return, Date Jun. 30, 2020                            
Highest Quarterly Return 32.73%                            
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                            
Lowest Quarterly Return, Date Jun. 30, 2022                            
Lowest Quarterly Return (26.41%)                            
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.                            
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Consumer Discretionary Fund | After Taxes on Distributions | Fidelity Advisor Consumer Discretionary Fund - Class A                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                          
Average Annual Return, Percent   15.78%                     10.82%   10.48%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Consumer Discretionary Fund | After Taxes on Distributions and Sales | Fidelity Advisor Consumer Discretionary 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   11.36%                     9.25%   9.10%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Consumer Discretionary Fund | SP001                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   S&P 500® Index                          
Average Annual Return, Percent   25.02%                     14.53%   13.10%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Consumer Discretionary Fund | F1505                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   MSCI U.S. IMI Consumer Discretionary 25-50 Index                          
Average Annual Return, Percent   24.48%                     16.03%   14.04%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Energy Fund | Fidelity Advisor Energy 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) [10] 0.00%                            
Management Fees (as a percentage of Assets) 0.71%                            
Distribution and Service (12b-1) Fees 0.25%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 0.98%                            
Expense Example, with Redemption, 1 Year $ 669                            
Expense Example, with Redemption, 3 Years 869                            
Expense Example, with Redemption, 5 Years 1,086                            
Expense Example, with Redemption, 10 Years 1,707                            
Expense Example, No Redemption, 1 Year 669                            
Expense Example, No Redemption, 3 Years 869                            
Expense Example, No Redemption, 5 Years 1,086                            
Expense Example, No Redemption, 10 Years $ 1,707                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   (2.10%)                     10.73%   3.44%
Annual Return [Percent]     3.87% 1.04% 61.92% 54.53% (32.73%) 9.75% (25.11%) (2.86%) 32.90% (20.65%)      
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Energy Fund | Fidelity Advisor Energy 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) [10] 0.00%                            
Management Fees (as a percentage of Assets) 0.71%                            
Distribution and Service (12b-1) Fees 0.50%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 1.23%                            
Expense Example, with Redemption, 1 Year $ 471                            
Expense Example, with Redemption, 3 Years 727                            
Expense Example, with Redemption, 5 Years 1,002                            
Expense Example, with Redemption, 10 Years 1,787                            
Expense Example, No Redemption, 1 Year 471                            
Expense Example, No Redemption, 3 Years 727                            
Expense Example, No Redemption, 5 Years 1,002                            
Expense Example, No Redemption, 10 Years $ 1,787                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   0.01%                     10.98%   3.41%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Energy Fund | Fidelity Advisor Energy 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) [11] 1.00%                            
Management Fees (as a percentage of Assets) 0.71%                            
Distribution and Service (12b-1) Fees 1.00%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 1.73%                            
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.                            
Expense Example, with Redemption, 1 Year $ 276                            
Expense Example, with Redemption, 3 Years 545                            
Expense Example, with Redemption, 5 Years 939                            
Expense Example, with Redemption, 10 Years 1,842                            
Expense Example, No Redemption, 1 Year 176                            
Expense Example, No Redemption, 3 Years 545                            
Expense Example, No Redemption, 5 Years 939                            
Expense Example, No Redemption, 10 Years $ 1,842                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   2.12%                     11.23%   3.45%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Energy Fund | Fidelity Advisor Energy 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) 0.69%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 0.71%                            
Expense Example, with Redemption, 1 Year $ 73                            
Expense Example, with Redemption, 3 Years 227                            
Expense Example, with Redemption, 5 Years 395                            
Expense Example, with Redemption, 10 Years 883                            
Expense Example, No Redemption, 1 Year 73                            
Expense Example, No Redemption, 3 Years 227                            
Expense Example, No Redemption, 5 Years 395                            
Expense Example, No Redemption, 10 Years $ 883                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   4.16%                     12.38%   4.35%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Energy Fund | Fidelity Advisor Energy 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) 0.56%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 0.58%                            
Expense Example, with Redemption, 1 Year $ 59                            
Expense Example, with Redemption, 3 Years 186                            
Expense Example, with Redemption, 5 Years 324                            
Expense Example, with Redemption, 10 Years 726                            
Expense Example, No Redemption, 1 Year 59                            
Expense Example, No Redemption, 3 Years 186                            
Expense Example, No Redemption, 5 Years 324                            
Expense Example, No Redemption, 10 Years $ 726                            
Annual Return, Inception Date Oct. 02, 2018                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   4.28%                     12.54% 5.26% [12]  
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Energy Fund                              
Prospectus Line Items                              
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity Advisor® Energy Fund /A, M, C, I, Z                              
Objective [Heading] Investment Objective                            
Objective, Primary [Text Block] Fidelity Advisor® Energy Fund seeks 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 59 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 pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 15 % of the average value of its portfolio.                            
Portfolio Turnover, Rate 15.00%                            
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 59 of the prospectus                            
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000                            
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] Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in the energy field including the conventional areas of oil, gas, electricity and coal, and newer sources of energy such as nuclear, geothermal, oil shale, and solar power. Energy products and services are those related to the exploration, extraction, production, sale, or distribution of energy resources, including oil, gas, electricity, coal, and nuclear, geothermal, and solar power. These companies may include, for example, integrated oil companies; drilling contractors and rig owners; drilling rig and equipment manufacturers and providers of supplies and services to companies engaged in oil and gas drilling; companies engaged in the exploration, production, refining, marketing, storage, or transportation of oil, gas, and/or refined products; and companies involved in the production and mining of coal, related products, and other consumable fuels. Fidelity may consider a company to be principally engaged in the designated business activity or activities based on: (i) the level of a company's assets, income, sales, or profits that are committed to, derived from, or related to the designated business activity or activities, or (ii) whether a third party has given the company an industry or sector classification consistent with the designated business activity or activities. Whether a company is principally engaged in the designated business activity or activities can be determined under any of these factors. Effective December 11, 2025, 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.   Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments. Proposed Reorganization. The Board of Trustees of Fidelity Advisor Series VII has unanimously approved an Agreement and Plan of Reorganization ("Agreement") between Fidelity Advisor ® Energy Fund and Energy Portfolio pursuant to which Fidelity Advisor ® Energy Fund would be reorganized on a tax-free basis with and into Energy Portfolio. As a result of the proposed Reorganization, shareholders of Fidelity Advisor ® Energy Fund would receive, respectively, corresponding shares of Energy Portfolio. The Agreement provides for the transfer of all of the assets of Fidelity Advisor ® Energy Fund in exchange for corresponding shares of Energy Portfolio equal in value to the net assets of Fidelity Advisor ® Energy Fund and the assumption by Energy Portfolio of all of the liabilities of Fidelity Advisor ® Energy Fund. After the exchange, Fidelity Advisor ® Energy Fund will distribute the Energy Portfolio shares to its shareholders pro rata, in liquidation of Fidelity Advisor ® Energy Fund. As a result, shareholders of Fidelity Advisor ® Energy Fund will become shareholders of Energy Portfolio (these transactions are collectively referred to as the "Reorganization"). The Reorganization, which does not require shareholder approval, is expected to take place on or about November 14, 2025. The Reorganization is expected to be a tax-free transaction. This means that neither Fidelity Advisor ® Energy Fund nor its shareholders will recognize any gain or loss as a direct result of the Reorganization. Effective after the close of business on the business day prior to the Reorganization, new positions in the fund may no longer be opened. Existing shareholders may continue to hold their shares and purchase additional shares through the reinvestment of dividend and capital gain distributions until the fund's Reorganization takes place. For more detailed information, please contact Fidelity at 1-877-208-0098.                            
Strategy Portfolio Concentration [Text] Normally investing at least 80% of assets in securities of companies principally engaged in the energy field including the conventional areas of oil, gas, electricity and coal, and newer sources of energy such as nuclear, geothermal, oil shale, and solar power.                            
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 an additional index over various periods of time. The additional index 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 an additional index 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 Jun. 30, 2025                            
Bar Chart, Year to Date Return 1.07%                            
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                            
Highest Quarterly Return, Date Mar. 31, 2022                            
Highest Quarterly Return 39.91%                            
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                            
Lowest Quarterly Return, Date Mar. 31, 2020                            
Lowest Quarterly Return (52.28%)                            
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.                            
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Energy Fund | After Taxes on Distributions | Fidelity Advisor Energy Fund - Class A                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                          
Average Annual Return, Percent   (2.33%)                     10.18%   3.06%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Energy Fund | After Taxes on Distributions and Sales | Fidelity Advisor Energy 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   (1.09%)                     8.40%   2.60%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Energy Fund | SP001                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   S&P 500® Index                          
Average Annual Return, Percent   25.02%                     14.53%   13.10%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Energy Fund | F1509                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   MSCI U.S. IMI Energy 25-50 Index                          
Average Annual Return, Percent   6.67%                     12.76%   4.51%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Financials Fund | Fidelity Advisor Financials 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) [13] 0.00%                            
Management Fees (as a percentage of Assets) 0.72%                            
Distribution and Service (12b-1) Fees 0.25%                            
Other Expenses (as a percentage of Assets): 0.03%                            
Expenses (as a percentage of Assets) 1.00%                            
Expense Example, with Redemption, 1 Year $ 671                            
Expense Example, with Redemption, 3 Years 875                            
Expense Example, with Redemption, 5 Years 1,096                            
Expense Example, with Redemption, 10 Years 1,729                            
Expense Example, No Redemption, 1 Year 671                            
Expense Example, No Redemption, 3 Years 875                            
Expense Example, No Redemption, 5 Years 1,096                            
Expense Example, No Redemption, 10 Years $ 1,729                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   24.55%                     11.43%   10.20%
Annual Return [Percent]     32.15% 14.05% (8.89%) 33.01% (0.23%) 33.76% (16.03%) 20.54% 18.34% (4.06%)      
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Financials Fund | Fidelity Advisor Financials 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) [13] 0.00%                            
Management Fees (as a percentage of Assets) 0.71%                            
Distribution and Service (12b-1) Fees 0.50%                            
Other Expenses (as a percentage of Assets): 0.03%                            
Expenses (as a percentage of Assets) 1.24%                            
Expense Example, with Redemption, 1 Year $ 472                            
Expense Example, with Redemption, 3 Years 730                            
Expense Example, with Redemption, 5 Years 1,007                            
Expense Example, with Redemption, 10 Years 1,797                            
Expense Example, No Redemption, 1 Year 472                            
Expense Example, No Redemption, 3 Years 730                            
Expense Example, No Redemption, 5 Years 1,007                            
Expense Example, No Redemption, 10 Years $ 1,797                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   27.24%                     11.67%   10.17%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Financials Fund | Fidelity Advisor Financials 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) [14] 1.00%                            
Management Fees (as a percentage of Assets) 0.71%                            
Distribution and Service (12b-1) Fees 1.00%                            
Other Expenses (as a percentage of Assets): 0.04%                            
Expenses (as a percentage of Assets) 1.75%                            
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.                            
Expense Example, with Redemption, 1 Year $ 278                            
Expense Example, with Redemption, 3 Years 551                            
Expense Example, with Redemption, 5 Years 949                            
Expense Example, with Redemption, 10 Years 1,864                            
Expense Example, No Redemption, 1 Year 178                            
Expense Example, No Redemption, 3 Years 551                            
Expense Example, No Redemption, 5 Years 949                            
Expense Example, No Redemption, 10 Years $ 1,864                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   30.16%                     11.90%   10.19%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Financials Fund | Fidelity Advisor Financials 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) 0.69%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.03%                            
Expenses (as a percentage of Assets) 0.72%                            
Expense Example, with Redemption, 1 Year $ 74                            
Expense Example, with Redemption, 3 Years 230                            
Expense Example, with Redemption, 5 Years 401                            
Expense Example, with Redemption, 10 Years 894                            
Expense Example, No Redemption, 1 Year 74                            
Expense Example, No Redemption, 3 Years 230                            
Expense Example, No Redemption, 5 Years 401                            
Expense Example, No Redemption, 10 Years $ 894                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   32.51%                     13.07%   11.17%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Financials Fund | Fidelity Advisor Financials 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) 0.56%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.03%                            
Expenses (as a percentage of Assets) 0.59%                            
Expense Example, with Redemption, 1 Year $ 60                            
Expense Example, with Redemption, 3 Years 189                            
Expense Example, with Redemption, 5 Years 329                            
Expense Example, with Redemption, 10 Years 738                            
Expense Example, No Redemption, 1 Year 60                            
Expense Example, No Redemption, 3 Years 189                            
Expense Example, No Redemption, 5 Years 329                            
Expense Example, No Redemption, 10 Years $ 738                            
Annual Return, Inception Date Oct. 02, 2018                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   32.70%                     13.21% 13.03% [15]  
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Financials Fund                              
Prospectus Line Items                              
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity Advisor® Financials Fund /A, M, C, I, Z                              
Objective [Heading] Investment Objective                            
Objective, Primary [Text Block] Fidelity Advisor® Financials Fund seeks 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 59 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 pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 49 % of the average value of its portfolio.                            
Portfolio Turnover, Rate 49.00%                            
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 59 of the prospectus                            
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000                            
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] Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in providing financial services to consumers and industry. These companies may include, for example, investment banks; brokerage and asset management firms; companies providing life, health, and/or property and casualty insurance; commercial banks; financial institutions providing mortgages and mortgage-related services, including mortgage real estate investment trusts (REITs); providers of personal loans and other consumer payment and finance services; credit agencies; stock exchanges; investment management firms; institutions providing custody services; and reinsurance companies. Fidelity may consider a company to be principally engaged in the designated business activity or activities based on: (i) the level of a company's assets, income, sales, or profits that are committed to, derived from, or related to the designated business activity or activities, or (ii) whether a third party has given the company an industry or sector classification consistent with the designated business activity or activities. Whether a company is principally engaged in the designated business activity or activities can be determined under any of these factors. Effective December 11, 2025, 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.   Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.                            
Strategy Portfolio Concentration [Text] Normally investing at least 80% of assets in securities of companies principally engaged in providing financial services to consumers and industry.                            
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 an additional index over various periods of time. The additional index 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 an additional index 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 Jun. 30, 2025                            
Bar Chart, Year to Date Return 7.82%                            
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                            
Highest Quarterly Return, Date Dec. 31, 2020                            
Highest Quarterly Return 30.61%                            
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                            
Lowest Quarterly Return, Date Mar. 31, 2020                            
Lowest Quarterly Return (35.63%)                            
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.                            
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Financials Fund | After Taxes on Distributions | Fidelity Advisor Financials Fund - Class A                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                          
Average Annual Return, Percent   23.13%                     10.40%   9.53%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Financials Fund | After Taxes on Distributions and Sales | Fidelity Advisor Financials 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   15.44%                     8.89%   8.25%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Financials Fund | SP001                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   S&P 500® Index                          
Average Annual Return, Percent   25.02%                     14.53%   13.10%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Financials Fund | IXZ92                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   MSCI U.S. IMI Financials 5% Capped Linked Index                          
Average Annual Return, Percent   30.21%                     11.96%   11.40%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | Fidelity Advisor Health Care 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) [16] 0.00%                            
Management Fees (as a percentage of Assets) 0.67%                            
Distribution and Service (12b-1) Fees 0.25%                            
Other Expenses (as a percentage of Assets): 0.01%                            
Expenses (as a percentage of Assets) 0.93%                            
Expense Example, with Redemption, 1 Year $ 664                            
Expense Example, with Redemption, 3 Years 854                            
Expense Example, with Redemption, 5 Years 1,060                            
Expense Example, with Redemption, 10 Years 1,652                            
Expense Example, No Redemption, 1 Year 664                            
Expense Example, No Redemption, 3 Years 854                            
Expense Example, No Redemption, 5 Years 1,060                            
Expense Example, No Redemption, 10 Years $ 1,652                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   (2.07%)                     3.53%   6.77%
Annual Return [Percent]     3.90% 3.81% (13.07%) 11.19% 21.08% 27.89% 7.34% 24.09% (10.33%) 5.95%      
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | Fidelity Advisor Health Care 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) [16] 0.00%                            
Management Fees (as a percentage of Assets) 0.67%                            
Distribution and Service (12b-1) Fees 0.50%                            
Other Expenses (as a percentage of Assets): 0.01%                            
Expenses (as a percentage of Assets) 1.18%                            
Expense Example, with Redemption, 1 Year $ 466                            
Expense Example, with Redemption, 3 Years 712                            
Expense Example, with Redemption, 5 Years 976                            
Expense Example, with Redemption, 10 Years 1,732                            
Expense Example, No Redemption, 1 Year 466                            
Expense Example, No Redemption, 3 Years 712                            
Expense Example, No Redemption, 5 Years 976                            
Expense Example, No Redemption, 10 Years $ 1,732                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   0.03%                     3.76%   6.75%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | Fidelity Advisor Health Care 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) [17] 1.00%                            
Management Fees (as a percentage of Assets) 0.67%                            
Distribution and Service (12b-1) Fees 1.00%                            
Other Expenses (as a percentage of Assets): 0.01%                            
Expenses (as a percentage of Assets) 1.68%                            
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.                            
Expense Example, with Redemption, 1 Year $ 271                            
Expense Example, with Redemption, 3 Years 530                            
Expense Example, with Redemption, 5 Years 913                            
Expense Example, with Redemption, 10 Years 1,788                            
Expense Example, No Redemption, 1 Year 171                            
Expense Example, No Redemption, 3 Years 530                            
Expense Example, No Redemption, 5 Years 913                            
Expense Example, No Redemption, 10 Years $ 1,788                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   2.24%                     3.98%   6.76%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | Fidelity Advisor Health Care 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) 0.67%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.01%                            
Expenses (as a percentage of Assets) 0.68%                            
Expense Example, with Redemption, 1 Year $ 69                            
Expense Example, with Redemption, 3 Years 218                            
Expense Example, with Redemption, 5 Years 379                            
Expense Example, with Redemption, 10 Years 847                            
Expense Example, No Redemption, 1 Year 69                            
Expense Example, No Redemption, 3 Years 218                            
Expense Example, No Redemption, 5 Years 379                            
Expense Example, No Redemption, 10 Years $ 847                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   4.17%                     5.04%   7.68%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | Fidelity Advisor Health Care 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) 0.55%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.01%                            
Expenses (as a percentage of Assets) 0.56%                            
Expense Example, with Redemption, 1 Year $ 57                            
Expense Example, with Redemption, 3 Years 179                            
Expense Example, with Redemption, 5 Years 313                            
Expense Example, with Redemption, 10 Years 701                            
Expense Example, No Redemption, 1 Year 57                            
Expense Example, No Redemption, 3 Years 179                            
Expense Example, No Redemption, 5 Years 313                            
Expense Example, No Redemption, 10 Years $ 701                            
Annual Return, Inception Date Oct. 02, 2018                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   4.31%                     5.17% 5.78% [18]  
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund                              
Prospectus Line Items                              
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity Advisor® Health Care Fund /A, M, C, I, Z                              
Objective [Heading] Investment Objective                            
Objective, Primary [Text Block] Fidelity Advisor® Health Care Fund seeks 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 59 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 pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 52 % of the average value of its portfolio.                            
Portfolio Turnover, Rate 52.00%                            
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 59 of the prospectus                            
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000                            
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] Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in the design, manufacture, or sale of products or services used for or in connection with health care or medicine. These companies may include, for example, companies engaged in the research, development, manufacturing, or marketing of products based on biotechnology research; companies engaged in research, development, or production of pharmaceuticals, including veterinary drugs; manufacturers, distributors, and wholesalers of health care equipment, devices, and supplies including drug delivery systems and eye care products; and owners and operators of health care facilities, HMOs, and other managed plans. Fidelity may consider a company to be principally engaged in the designated business activity or activities based on: (i) the level of a company's assets, income, sales, or profits that are committed to, derived from, or related to the designated business activity or activities, or (ii) whether a third party has given the company an industry or sector classification consistent with the designated business activity or activities. Whether a company is principally engaged in the designated business activity or activities can be determined under any of these factors. Effective December 11, 2025, 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.   Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.                            
Strategy Portfolio Concentration [Text] Normally investing at least 80% of assets in securities of companies principally engaged in the design, manufacture, or sale of products or services used for or in connection with health care or medicine.                            
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 an additional index over various periods of time. The additional index 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 an additional index 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 Jun. 30, 2025                            
Bar Chart, Year to Date Return (3.49%)                            
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                            
Highest Quarterly Return, Date Dec. 31, 2019                            
Highest Quarterly Return 21.25%                            
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                            
Lowest Quarterly Return, Date Dec. 31, 2018                            
Lowest Quarterly Return (15.00%)                            
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.                            
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | After Taxes on Distributions | Fidelity Advisor Health Care Fund - Class A                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                          
Average Annual Return, Percent   (4.58%)                     2.42%   5.84%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | After Taxes on Distributions and Sales | Fidelity Advisor Health Care 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   0.63%                     2.74%   5.32%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | SP001                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   S&P 500® Index                          
Average Annual Return, Percent   25.02%                     14.53%   13.10%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Health Care Fund | F1513                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   MSCI U.S. IMI Health Care 25-50 Index                          
Average Annual Return, Percent   2.75%                     7.29%   8.90%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | Fidelity Advisor Industrials 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) [19] 0.00%                            
Management Fees (as a percentage of Assets) 0.70%                            
Distribution and Service (12b-1) Fees 0.25%                            
Other Expenses (as a percentage of Assets): 0.03%                            
Expenses (as a percentage of Assets) 0.98%                            
Expense Example, with Redemption, 1 Year $ 669                            
Expense Example, with Redemption, 3 Years 869                            
Expense Example, with Redemption, 5 Years 1,086                            
Expense Example, with Redemption, 10 Years 1,707                            
Expense Example, No Redemption, 1 Year 669                            
Expense Example, No Redemption, 3 Years 869                            
Expense Example, No Redemption, 5 Years 1,086                            
Expense Example, No Redemption, 10 Years $ 1,707                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   15.94%                     10.50%   9.15%
Annual Return [Percent]     23.01% 22.65% (10.62%) 16.60% 11.17% 27.75% (15.58%) 19.56% 15.48% (2.19%)      
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | Fidelity Advisor Industrials 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) [19] 0.00%                            
Management Fees (as a percentage of Assets) 0.70%                            
Distribution and Service (12b-1) Fees 0.50%                            
Other Expenses (as a percentage of Assets): 0.03%                            
Expenses (as a percentage of Assets) 1.23%                            
Expense Example, with Redemption, 1 Year $ 471                            
Expense Example, with Redemption, 3 Years 727                            
Expense Example, with Redemption, 5 Years 1,002                            
Expense Example, with Redemption, 10 Years 1,787                            
Expense Example, No Redemption, 1 Year 471                            
Expense Example, No Redemption, 3 Years 727                            
Expense Example, No Redemption, 5 Years 1,002                            
Expense Example, No Redemption, 10 Years $ 1,787                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   18.42%                     10.74%   9.12%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | Fidelity Advisor Industrials 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) [20] 1.00%                            
Management Fees (as a percentage of Assets) 0.71%                            
Distribution and Service (12b-1) Fees 1.00%                            
Other Expenses (as a percentage of Assets): 0.03%                            
Expenses (as a percentage of Assets) 1.74%                            
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.                            
Expense Example, with Redemption, 1 Year $ 277                            
Expense Example, with Redemption, 3 Years 548                            
Expense Example, with Redemption, 5 Years 944                            
Expense Example, with Redemption, 10 Years 1,851                            
Expense Example, No Redemption, 1 Year 177                            
Expense Example, No Redemption, 3 Years 548                            
Expense Example, No Redemption, 5 Years 944                            
Expense Example, No Redemption, 10 Years $ 1,851                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   21.07%                     10.98%   9.13%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | Fidelity Advisor Industrials 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) 0.68%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.03%                            
Expenses (as a percentage of Assets) 0.71%                            
Expense Example, with Redemption, 1 Year $ 73                            
Expense Example, with Redemption, 3 Years 227                            
Expense Example, with Redemption, 5 Years 395                            
Expense Example, with Redemption, 10 Years 883                            
Expense Example, No Redemption, 1 Year 73                            
Expense Example, No Redemption, 3 Years 227                            
Expense Example, No Redemption, 5 Years 395                            
Expense Example, No Redemption, 10 Years $ 883                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   23.35%                     12.12%   10.09%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | Fidelity Advisor Industrials 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) 0.56%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.03%                            
Expenses (as a percentage of Assets) 0.59%                            
Expense Example, with Redemption, 1 Year $ 60                            
Expense Example, with Redemption, 3 Years 189                            
Expense Example, with Redemption, 5 Years 329                            
Expense Example, with Redemption, 10 Years 738                            
Expense Example, No Redemption, 1 Year 60                            
Expense Example, No Redemption, 3 Years 189                            
Expense Example, No Redemption, 5 Years 329                            
Expense Example, No Redemption, 10 Years $ 738                            
Annual Return, Inception Date Oct. 02, 2018                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   23.50%                     12.26% 10.05% [21]  
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund                              
Prospectus Line Items                              
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity Advisor® Industrials Fund /A, M, C, I, Z                              
Objective [Heading] Investment Objective                            
Objective, Primary [Text Block] Fidelity Advisor® Industrials Fund seeks 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 59 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 pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, 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 59 of the prospectus                            
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000                            
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] Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in the research, development, manufacture, distribution, supply, or sale of industrial products, services, or equipment. Industrial products, services and equipment, such as capital goods, construction services, machinery, commercial services, and transportation, are generally considered to be sensitive to the business cycle. These companies may include, for example, manufacturers of civil or military aerospace and defense equipment, building components, and home improvement products and equipment; civil engineering companies and large-scale contractors; companies that produce electrical components or equipment; manufacturers of industrial machinery and industrial components and products; manufacturers of agricultural machinery and equipment; providers of commercial printing services; companies providing business support services related to human capital management and office supplies, providers of commercial data processing and business outsourcing services, environmental and facilities maintenance; companies providing transportation services, including airlines, couriers, marine, road & rail, and transportation infrastructure. Fidelity may consider a company to be principally engaged in the designated business activity or activities based on: (i) the level of a company's assets, income, sales, or profits that are committed to, derived from, or related to the designated business activity or activities, or (ii) whether a third party has given the company an industry or sector classification consistent with the designated business activity or activities. Whether a company is principally engaged in the designated business activity or activities can be determined under any of these factors. Effective December 11, 2025, 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.   Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.                            
Strategy Portfolio Concentration [Text] Normally investing at least 80% of assets in securities of companies principally engaged in the research, development, manufacture, distribution, supply, or sale of industrial products, services, or equipment.                            
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 an additional index over various periods of time. The additional index 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 an additional index 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 Jun. 30, 2025                            
Bar Chart, Year to Date Return 16.60%                            
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                            
Highest Quarterly Return, Date Jun. 30, 2020                            
Highest Quarterly Return 19.81%                            
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                            
Lowest Quarterly Return, Date Mar. 31, 2020                            
Lowest Quarterly Return (28.79%)                            
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.                            
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | After Taxes on Distributions | Fidelity Advisor Industrials Fund - Class A                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                          
Average Annual Return, Percent   14.87%                     8.58%   7.29%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | After Taxes on Distributions and Sales | Fidelity Advisor Industrials 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   10.21%                     7.90%   6.88%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | SP001                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   S&P 500® Index                          
Average Annual Return, Percent   25.02%                     14.53%   13.10%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Industrials Fund | F1511                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   MSCI U.S. IMI Industrials 25-50 Index                          
Average Annual Return, Percent   17.05%                     12.27%   10.95%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | Fidelity Advisor Semiconductors 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) [22] 0.00%                            
Management Fees (as a percentage of Assets) 0.67%                            
Distribution and Service (12b-1) Fees 0.25%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 0.94%                            
Expense Example, with Redemption, 1 Year $ 665                            
Expense Example, with Redemption, 3 Years 857                            
Expense Example, with Redemption, 5 Years 1,065                            
Expense Example, with Redemption, 10 Years 1,663                            
Expense Example, No Redemption, 1 Year 665                            
Expense Example, No Redemption, 3 Years 857                            
Expense Example, No Redemption, 5 Years 1,065                            
Expense Example, No Redemption, 10 Years $ 1,663                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   35.46%                     28.34%   24.68%
Annual Return [Percent]     43.72% 74.91% (35.05%) 57.52% 43.62% 63.75% (12.49%) 34.24% 32.42% 2.34%      
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | Fidelity Advisor Semiconductors 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) [22] 0.00%                            
Management Fees (as a percentage of Assets) 0.67%                            
Distribution and Service (12b-1) Fees 0.50%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 1.19%                            
Expense Example, with Redemption, 1 Year $ 467                            
Expense Example, with Redemption, 3 Years 715                            
Expense Example, with Redemption, 5 Years 981                            
Expense Example, with Redemption, 10 Years 1,743                            
Expense Example, No Redemption, 1 Year 467                            
Expense Example, No Redemption, 3 Years 715                            
Expense Example, No Redemption, 5 Years 981                            
Expense Example, No Redemption, 10 Years $ 1,743                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   38.36%                     28.62%   24.60%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | Fidelity Advisor Semiconductors 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) [23] 1.00%                            
Management Fees (as a percentage of Assets) 0.67%                            
Distribution and Service (12b-1) Fees 1.00%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 1.69%                            
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.                            
Expense Example, with Redemption, 1 Year $ 272                            
Expense Example, with Redemption, 3 Years 533                            
Expense Example, with Redemption, 5 Years 918                            
Expense Example, with Redemption, 10 Years 1,799                            
Expense Example, No Redemption, 1 Year 172                            
Expense Example, No Redemption, 3 Years 533                            
Expense Example, No Redemption, 5 Years 918                            
Expense Example, No Redemption, 10 Years $ 1,799                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   41.64%                     28.89%   24.65%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | Fidelity Advisor Semiconductors 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) 0.67%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 0.69%                            
Expense Example, with Redemption, 1 Year $ 70                            
Expense Example, with Redemption, 3 Years 221                            
Expense Example, with Redemption, 5 Years 384                            
Expense Example, with Redemption, 10 Years 859                            
Expense Example, No Redemption, 1 Year 70                            
Expense Example, No Redemption, 3 Years 221                            
Expense Example, No Redemption, 5 Years 384                            
Expense Example, No Redemption, 10 Years $ 859                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   44.08%                     30.22%   25.77%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | Fidelity Advisor Semiconductors 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) 0.55%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 0.57%                            
Expense Example, with Redemption, 1 Year $ 58                            
Expense Example, with Redemption, 3 Years 183                            
Expense Example, with Redemption, 5 Years 318                            
Expense Example, with Redemption, 10 Years 714                            
Expense Example, No Redemption, 1 Year 58                            
Expense Example, No Redemption, 3 Years 183                            
Expense Example, No Redemption, 5 Years 318                            
Expense Example, No Redemption, 10 Years $ 714                            
Annual Return, Inception Date Oct. 02, 2018                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   44.25%                     30.38% 29.84% [24]  
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund                              
Prospectus Line Items                              
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity Advisor® Semiconductors Fund /A, M, C, I, Z                              
Objective [Heading] Investment Objective                            
Objective, Primary [Text Block] Fidelity Advisor® Semiconductors Fund seeks 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 59 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 pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 65 % of the average value of its portfolio.                            
Portfolio Turnover, Rate 65.00%                            
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 59 of the prospectus                            
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000                            
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] Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in the design, manufacture, or sale of semiconductors and semiconductor equipment. These companies may include, for example, manufacturers of semiconductor equipment and related products. Fidelity may consider a company to be principally engaged in the designated business activity or activities based on: (i) the level of a company's assets, income, sales, or profits that are committed to, derived from, or related to the designated business activity or activities, or (ii) whether a third party has given the company an industry or sector classification consistent with the designated business activity or activities. Whether a company is principally engaged in the designated business activity or activities can be determined under any of these factors. Effective December 11, 2025, 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.   Also investing primarily in companies engaged in the design, manufacture, or sale of electronic components (semiconductors, connectors, printed circuit boards and other components); equipment vendors to electronic component manufacturers; electronic component distributors; and electronic instruments and electronic systems vendors. Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.                            
Strategy Portfolio Concentration [Text] Normally investing at least 80% of assets in securities of companies principally engaged in the design, manufacture, or sale of semiconductors and semiconductor equipment.                            
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 an additional index over various periods of time. The additional index 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 an additional index 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 Jun. 30, 2025                            
Bar Chart, Year to Date Return 11.35%                            
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                            
Highest Quarterly Return, Date Mar. 31, 2023                            
Highest Quarterly Return 38.96%                            
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                            
Lowest Quarterly Return, Date Jun. 30, 2022                            
Lowest Quarterly Return (28.90%)                            
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.                            
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | After Taxes on Distributions | Fidelity Advisor Semiconductors Fund - Class A                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                          
Average Annual Return, Percent   33.43%                     26.98%   22.56%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | After Taxes on Distributions and Sales | Fidelity Advisor Semiconductors 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   22.56%                     23.23%   20.30%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | SP001                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   S&P 500® Index                          
Average Annual Return, Percent   25.02%                     14.53%   13.10%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Semiconductors Fund | F1508                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   MSCI U.S. IMI Semiconductors & Semiconductor Equipment 25-50 Index                          
Average Annual Return, Percent   37.03%                     30.57%   25.27%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Technology Fund | Fidelity Advisor Technology 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) [25] 0.00%                            
Management Fees (as a percentage of Assets) 0.66%                            
Distribution and Service (12b-1) Fees 0.25%                            
Other Expenses (as a percentage of Assets): 0.01%                            
Expenses (as a percentage of Assets) 0.92%                            
Expense Example, with Redemption, 1 Year $ 663                            
Expense Example, with Redemption, 3 Years 851                            
Expense Example, with Redemption, 5 Years 1,055                            
Expense Example, with Redemption, 10 Years 1,641                            
Expense Example, No Redemption, 1 Year 663                            
Expense Example, No Redemption, 3 Years 851                            
Expense Example, No Redemption, 5 Years 1,055                            
Expense Example, No Redemption, 10 Years $ 1,641                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   27.27%                     21.96%   20.94%
Annual Return [Percent]     35.03% 59.19% (36.16%) 27.25% 63.90% 50.55% (7.79%) 49.36% 11.80% 7.02%      
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Technology Fund | Fidelity Advisor Technology 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) [25] 0.00%                            
Management Fees (as a percentage of Assets) 0.66%                            
Distribution and Service (12b-1) Fees 0.50%                            
Other Expenses (as a percentage of Assets): 0.01%                            
Expenses (as a percentage of Assets) 1.17%                            
Expense Example, with Redemption, 1 Year $ 465                            
Expense Example, with Redemption, 3 Years 709                            
Expense Example, with Redemption, 5 Years 971                            
Expense Example, with Redemption, 10 Years 1,721                            
Expense Example, No Redemption, 1 Year 465                            
Expense Example, No Redemption, 3 Years 709                            
Expense Example, No Redemption, 5 Years 971                            
Expense Example, No Redemption, 10 Years $ 1,721                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   29.99%                     22.23%   20.92%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Technology Fund | Fidelity Advisor Technology 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) [26] 1.00%                            
Management Fees (as a percentage of Assets) 0.66%                            
Distribution and Service (12b-1) Fees 1.00%                            
Other Expenses (as a percentage of Assets): 0.01%                            
Expenses (as a percentage of Assets) 1.67%                            
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.                            
Expense Example, with Redemption, 1 Year $ 270                            
Expense Example, with Redemption, 3 Years 526                            
Expense Example, with Redemption, 5 Years 907                            
Expense Example, with Redemption, 10 Years 1,777                            
Expense Example, No Redemption, 1 Year 170                            
Expense Example, No Redemption, 3 Years 526                            
Expense Example, No Redemption, 5 Years 907                            
Expense Example, No Redemption, 10 Years $ 1,777                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   33.03%                     22.47%   20.92%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Technology Fund | Fidelity Advisor Technology 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) 0.66%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.01%                            
Expenses (as a percentage of Assets) 0.67%                            
Expense Example, with Redemption, 1 Year $ 68                            
Expense Example, with Redemption, 3 Years 214                            
Expense Example, with Redemption, 5 Years 373                            
Expense Example, with Redemption, 10 Years 835                            
Expense Example, No Redemption, 1 Year 68                            
Expense Example, No Redemption, 3 Years 214                            
Expense Example, No Redemption, 5 Years 373                            
Expense Example, No Redemption, 10 Years $ 835                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   35.37%                     23.72%   21.99%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Technology Fund | Fidelity Advisor Technology 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) 0.54%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.01%                            
Expenses (as a percentage of Assets) 0.55%                            
Expense Example, with Redemption, 1 Year $ 56                            
Expense Example, with Redemption, 3 Years 176                            
Expense Example, with Redemption, 5 Years 307                            
Expense Example, with Redemption, 10 Years 689                            
Expense Example, No Redemption, 1 Year 56                            
Expense Example, No Redemption, 3 Years 176                            
Expense Example, No Redemption, 5 Years 307                            
Expense Example, No Redemption, 10 Years $ 689                            
Annual Return, Inception Date Oct. 02, 2018                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   35.54%                     23.88% 21.91% [27]  
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Technology Fund                              
Prospectus Line Items                              
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity Advisor® Technology Fund /A, M, C, I, Z                              
Objective [Heading] Investment Objective                            
Objective, Primary [Text Block] Fidelity Advisor® Technology Fund seeks 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 59 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 pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 50 % of the average value of its portfolio.                            
Portfolio Turnover, Rate 50.00%                            
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 59 of the prospectus                            
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000                            
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] Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in offering, using, or developing products, processes, or services that will provide or will benefit significantly from technological advances and improvements. These companies may include, for example, manufacturers of communications equipment, products, and services, personal computers and other computer hardware components and peripherals; providers of information technology and systems integration services; companies developing and producing database management, home entertainment, educational, specialty, enterprise, and business software; manufacturers of electronic equipment, instruments or components, including copiers and faxes; semiconductor and related equipment manufacturers; and other information technology companies. Fidelity may consider a company to be principally engaged in the designated business activity or activities based on: (i) the level of a company's assets, income, sales, or profits that are committed to, derived from, or related to the designated business activity or activities, or (ii) whether a third party has given the company an industry or sector classification consistent with the designated business activity or activities. Whether a company is principally engaged in the designated business activity or activities can be determined under any of these factors. Effective December 11, 2025, 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.   Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments. Proposed Reorganization. The Board of Trustees of Fidelity Advisor Series VII has unanimously approved an Agreement and Plan of Reorganization ("Agreement") between Fidelity Advisor ® Technology Fund and Technology Portfolio pursuant to which Fidelity Advisor ® Technology Fund would be reorganized on a tax-free basis with and into Technology Portfolio. As a result of the proposed Reorganization, shareholders of Fidelity Advisor ® Technology Fund would receive, respectively, corresponding shares of Technology Portfolio. The Agreement provides for the transfer of all of the assets of Fidelity Advisor ® Technology Fund in exchange for corresponding shares of Technology Portfolio equal in value to the net assets of Fidelity Advisor ® Technology Fund and the assumption by Technology Portfolio of all of the liabilities of Fidelity Advisor ® Technology Fund. After the exchange, Fidelity Advisor ® Technology Fund will distribute the Technology Portfolio shares to its shareholders pro rata, in liquidation of Fidelity Advisor ® Technology Fund. As a result, shareholders of Fidelity Advisor ® Technology Fund will become shareholders of Technology Portfolio (these transactions are collectively referred to as the "Reorganization"). The Reorganization, which does not require shareholder approval, is expected to take place on or about November 14, 2025. The Reorganization is expected to be a tax-free transaction. This means that neither Fidelity Advisor ® Technology Fund nor its shareholders will recognize any gain or loss as a direct result of the Reorganization. Effective after the close of business on the business day prior to the Reorganization, new positions in the fund may no longer be opened. Existing shareholders may continue to hold their shares and purchase additional shares through the reinvestment of dividend and capital gain distributions until the fund's Reorganization takes place. For more detailed information, please contact Fidelity at 1-877-208-0098.                            
Strategy Portfolio Concentration [Text] Normally investing at least 80% of assets in securities of companies principally engaged in offering, using, or developing products, processes, or services that will provide or will benefit significantly from technological advances and improvements.                            
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 an additional index over various periods of time. The additional index 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 an additional index 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 Jun. 30, 2025                            
Bar Chart, Year to Date Return 7.13%                            
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                            
Highest Quarterly Return, Date Jun. 30, 2020                            
Highest Quarterly Return 36.16%                            
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                            
Lowest Quarterly Return, Date Jun. 30, 2022                            
Lowest Quarterly Return (25.44%)                            
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.                            
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Technology Fund | After Taxes on Distributions | Fidelity Advisor Technology Fund - Class A                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                          
Average Annual Return, Percent   25.10%                     19.80%   18.64%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Technology Fund | After Taxes on Distributions and Sales | Fidelity Advisor Technology 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   17.80%                     17.38%   16.95%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Technology Fund | SP001                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   S&P 500® Index                          
Average Annual Return, Percent   25.02%                     14.53%   13.10%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Technology Fund | F1525                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   MSCI U.S. IMI Information Technology 25-50 Index                          
Average Annual Return, Percent   29.38%                     21.55%   20.54%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Utilities Fund | Fidelity Advisor Utilities 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) [28] 0.00%                            
Management Fees (as a percentage of Assets) 0.71%                            
Distribution and Service (12b-1) Fees 0.25%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 0.98%                            
Expense Example, with Redemption, 1 Year $ 669                            
Expense Example, with Redemption, 3 Years 869                            
Expense Example, with Redemption, 5 Years 1,086                            
Expense Example, with Redemption, 10 Years 1,707                            
Expense Example, No Redemption, 1 Year 669                            
Expense Example, No Redemption, 3 Years 869                            
Expense Example, No Redemption, 5 Years 1,086                            
Expense Example, No Redemption, 10 Years $ 1,707                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   20.88%                     7.79%   8.59%
Annual Return [Percent]     28.26% (1.71%) 4.90% 17.33% (0.51%) 22.02% 8.34% 17.31% 13.53% (10.97%)      
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Utilities Fund | Fidelity Advisor Utilities 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) [28] 0.00%                            
Management Fees (as a percentage of Assets) 0.71%                            
Distribution and Service (12b-1) Fees 0.50%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 1.23%                            
Expense Example, with Redemption, 1 Year $ 471                            
Expense Example, with Redemption, 3 Years 727                            
Expense Example, with Redemption, 5 Years 1,002                            
Expense Example, with Redemption, 10 Years 1,787                            
Expense Example, No Redemption, 1 Year 471                            
Expense Example, No Redemption, 3 Years 727                            
Expense Example, No Redemption, 5 Years 1,002                            
Expense Example, No Redemption, 10 Years $ 1,787                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   23.42%                     8.00%   8.54%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Utilities Fund | Fidelity Advisor Utilities 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) [29] 1.00%                            
Management Fees (as a percentage of Assets) 0.71%                            
Distribution and Service (12b-1) Fees 1.00%                            
Other Expenses (as a percentage of Assets): 0.02%                            
Expenses (as a percentage of Assets) 1.73%                            
Expenses Deferred Charges [Text Block] On Class C shares redeemed less than one year after purchase.                            
Expense Example, with Redemption, 1 Year $ 276                            
Expense Example, with Redemption, 3 Years 545                            
Expense Example, with Redemption, 5 Years 939                            
Expense Example, with Redemption, 10 Years 1,842                            
Expense Example, No Redemption, 1 Year 176                            
Expense Example, No Redemption, 3 Years 545                            
Expense Example, No Redemption, 5 Years 939                            
Expense Example, No Redemption, 10 Years $ 1,842                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   26.28%                     8.25%   8.58%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Utilities Fund | Fidelity Advisor Utilities 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) 0.69%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.03%                            
Expenses (as a percentage of Assets) 0.72%                            
Expense Example, with Redemption, 1 Year $ 74                            
Expense Example, with Redemption, 3 Years 230                            
Expense Example, with Redemption, 5 Years 401                            
Expense Example, with Redemption, 10 Years 894                            
Expense Example, No Redemption, 1 Year 74                            
Expense Example, No Redemption, 3 Years 230                            
Expense Example, No Redemption, 5 Years 401                            
Expense Example, No Redemption, 10 Years $ 894                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   28.59%                     9.36%   9.54%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Utilities Fund | Fidelity Advisor Utilities 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) 0.57%                            
Distribution and Service (12b-1) Fees 0.00%                            
Other Expenses (as a percentage of Assets): 0.03%                            
Expenses (as a percentage of Assets) 0.60%                            
Expense Example, with Redemption, 1 Year $ 61                            
Expense Example, with Redemption, 3 Years 192                            
Expense Example, with Redemption, 5 Years 335                            
Expense Example, with Redemption, 10 Years 750                            
Expense Example, No Redemption, 1 Year 61                            
Expense Example, No Redemption, 3 Years 192                            
Expense Example, No Redemption, 5 Years 335                            
Expense Example, No Redemption, 10 Years $ 750                            
Annual Return, Inception Date Oct. 02, 2018                            
Average Annual Return, Label [Optional Text]   Return Before Taxes                          
Average Annual Return, Percent   28.73%                     9.50% 10.56% [30]  
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Utilities Fund                              
Prospectus Line Items                              
Risk/Return [Heading] Fund Summary Fund /Class: Fidelity Advisor® Utilities Fund /A, M, C, I, Z                              
Objective [Heading] Investment Objective                            
Objective, Primary [Text Block] Fidelity Advisor® Utilities Fund seeks 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 59 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 pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when fund shares are held in a taxable account. These costs, which are not reflected in annual operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 119 % of the average value of its portfolio.                            
Portfolio Turnover, Rate 119.00%                            
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 59 of the prospectus                            
Expense Breakpoint, Minimum Investment Required [Amount] $ 50,000                            
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] Normally investing primarily in common stocks. Normally investing at least 80% of assets in securities of companies principally engaged in the utilities industry and companies deriving a majority of their revenues from their utility operations. These companies may include, for example, companies that produce electricity, including nuclear and non-nuclear facilities; companies that distribute and transmit natural and manufactured gas; water treatment and other utility companies; companies that operate as independent power producers, gas and power marketing and trading specialists and/or integrated energy merchants; and companies that engage in the generation and distribution of electricity using renewable sources. Fidelity may consider a company to be principally engaged in the designated business activity or activities based on: (i) the level of a company's assets, income, sales, or profits that are committed to, derived from, or related to the designated business activity or activities, or (ii) whether a third party has given the company an industry or sector classification consistent with the designated business activity or activities. Whether a company is principally engaged in the designated business activity or activities can be determined under any of these factors. Effective December 11, 2025, 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.   Investing in domestic and foreign issuers. Using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments. Proposed Reorganization. The Board of Trustees of Fidelity Advisor Series VII has unanimously approved an Agreement and Plan of Reorganization ("Agreement") between Fidelity Advisor ® Utilities Fund and Utilities Portfolio pursuant to which Fidelity Advisor ® Utilities Fund would be reorganized on a tax-free basis with and into Utilities Portfolio. As a result of the proposed Reorganization, shareholders of Fidelity Advisor ® Utilities Fund would receive, respectively, corresponding shares of Utilities Portfolio. The Agreement provides for the transfer of all of the assets of Fidelity Advisor ® Utilities Fund in exchange for corresponding shares of Utilities Portfolio equal in value to the net assets of Fidelity Advisor ® Utilities Fund and the assumption by Utilities Portfolio of all of the liabilities of Fidelity Advisor ® Utilities Fund. After the exchange, Fidelity Advisor ® Utilities Fund will distribute the Utilities Portfolio shares to its shareholders pro rata, in liquidation of Fidelity Advisor ® Utilities Fund. As a result, shareholders of Fidelity Advisor ® Utilities Fund will become shareholders of Utilities Portfolio (these transactions are collectively referred to as the "Reorganization"). The Reorganization, which does not require shareholder approval, is expected to take place on or about October 17, 2025. The Reorganization is expected to be a tax-free transaction. This means that neither Fidelity Advisor ® Utilities Fund nor its shareholders will recognize any gain or loss as a direct result of the Reorganization. Effective after the close of business on the business day prior to the Reorganization, new positions in the fund may no longer be opened. Existing shareholders may continue to hold their shares and purchase additional shares through the reinvestment of dividend and capital gain distributions until the fund's Reorganization takes place. For more detailed information, please contact Fidelity at 1-877-208-0098 .                            
Strategy Portfolio Concentration [Text] Normally investing at least 80% of assets in securities of companies principally engaged in the utilities industry and companies deriving a majority of their revenues from their utility operations.                            
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 an additional index over various periods of time. The additional index 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 an additional index 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 Jun. 30, 2025                            
Bar Chart, Year to Date Return 6.04%                            
Highest Quarterly Return, Label [Optional Text]    Highest Quarter Return                            
Highest Quarterly Return, Date Sep. 30, 2024                            
Highest Quarterly Return 18.45%                            
Lowest Quarterly Return, Label [Optional Text]    Lowest Quarter Return                            
Lowest Quarterly Return, Date Mar. 31, 2020                            
Lowest Quarterly Return (18.27%)                            
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.                            
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Utilities Fund | After Taxes on Distributions | Fidelity Advisor Utilities Fund - Class A                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   Return After Taxes on Distributions                          
Average Annual Return, Percent   19.29%                     6.87%   7.56%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Utilities Fund | After Taxes on Distributions and Sales | Fidelity Advisor Utilities 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   13.37%                     5.98%   6.72%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Utilities Fund | SP001                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   S&P 500® Index                          
Average Annual Return, Percent   25.02%                     14.53%   13.10%
FidelityAdvisorFocusFunds-AMCIZComboPRO | Fidelity Advisor Utilities Fund | F1528                              
Prospectus Line Items                              
Average Annual Return, Label [Optional Text]   MSCI U.S. IMI Utilities 25-50 Index                          
Average Annual Return, Percent   23.20%                     6.14%   8.30%
Document Type 485BPOS                            
Registrant Name Fidelity Advisor Series VII                            
[1]
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.
[2]
B On Class C shares redeemed less than one year after purchase.
[3]
A From October 2, 2018 .
[4]
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.
[5]
B On Class C shares redeemed less than one year after purchase.
[6]
A From October 2, 2018 .
[7]
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.
[8]
B On Class C shares redeemed less than one year after purchase.
[9]
A From October 2, 2018 .
[10]
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.
[11]
B On Class C shares redeemed less than one year after purchase.
[12]
A From October 2, 2018 .
[13]
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.
[14]
B On Class C shares redeemed less than one year after purchase.
[15]
A From October 2, 2018 .
[16]
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.
[17]
B On Class C shares redeemed less than one year after purchase.
[18]
A From October 2, 2018 .
[19]
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.
[20]
B On Class C shares redeemed less than one year after purchase.
[21]
A From October 2, 2018 .
[22]
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.
[23]
B On Class C shares redeemed less than one year after purchase.
[24]
A From October 2, 2018 .
[25]
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.
[26]
B On Class C shares redeemed less than one year after purchase.
[27]
A From October 2, 2018 .
[28]
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.
[29]
B On Class C shares redeemed less than one year after purchase.
[30]
A From October 2, 2018 .