v3.24.4
Label Element Value
Prospectus [Line Items] rr_ProspectusLineItems  
Document Type dei_DocumentType 485BPOS
Document Period End Date dei_DocumentPeriodEndDate Dec. 31, 2024
Entity Registrant Name dei_EntityRegistrantName Putnam Investment Funds
Entity Central Index Key dei_EntityCentralIndexKey 0000932101
Entity Inv Company Type dei_EntityInvCompanyType N-1A
Amendment Flag dei_AmendmentFlag false
Prospectus 1 [Member] | Putnam Government Money Market Fund  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading Fund Summary
Objective [Heading] rr_ObjectiveHeading Goal
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks as high a rate of current income as the Investment Manager (as defined below) believes is consistent with preservation of capital and maintenance of liquidity.

Expense [Heading] rr_ExpenseHeading Fees and expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following tables describe the fees and expenses you may pay if 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. Information about sales charge discounts is available from your financial professional and in the Appendix to the fund’s prospectus.

Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder Fees (fees paid directly from your investment)
Operating Expenses Caption [Text] rr_OperatingExpensesCaption Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment)
Expense Example [Heading] rr_ExpenseExampleHeading Example
Expense Example Narrative [Text Block] rr_ExpenseExampleNarrativeTextBlock

The following hypothetical example is intended to help you compare the cost of investing in the fund with the cost of investing in other funds. It assumes that you invest $10,000 in the fund for the time periods indicated and then, except as indicated, redeem or hold all your shares at the end of those periods. It assumes a 5% return on your investment each year and that the fund’s operating expenses remain the same. Your actual costs may be higher or lower.

Strategy [Heading] rr_StrategyHeading Investments, risks, and performance
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

Investments

We invest at least 99.5 percent of the fund’s total assets in cash, U.S. government securities and repurchase agreements that are fully collateralized by U.S. government securities or cash. We invest mainly in debt securities that are obligations of the U.S. government, its agencies and instrumentalities and accordingly are backed by the full faith and credit of the United States (e.g., U.S. Treasury bills) or by the credit of a federal agency or government-sponsored entity (e.g.,securities issued by Fannie Mae and Freddie Mac). The U.S. government securities in which we invest may also include variable and floating rate instruments and when-issued and delayed delivery securities (i.e., payment or delivery of the securities occurs at a future date for a predetermined price). Under normal circumstances, we invest at least 80% of the fund’s net assets in U.S. government securities and repurchase agreements that are fully collateralized by U.S. government securities. This policy may be changed only after 60 days’ notice to shareholders. The securities purchased by the fund are subject to quality, maturity, diversification and other requirements pursuant to rules promulgated by the Securities and Exchange Commission. We may consider, among other factors, credit and interest rate risks and characteristics of the issuer or counterparty, as well as general market conditions, when deciding whether to buy or sell investments.

Risk [Heading] rr_RiskHeading Risks
Risk [Text Block] rr_RiskTextBlock

It is important to understand that you can lose money by investing in the fund.

The value of investments in the fund’s portfolio may fall or fail to rise over extended periods of time for a variety of reasons, including general economic, political or financial market conditions, investor sentiment and market perceptions, government actions, geopolitical events or changes, outbreaks of infectious illnesses or other widespread public health issues, and factors related to a specific issuer, asset class, geography, industry or sector. These and other factors may lead to increased volatility and reduced liquidity in the fund’s portfolio holdings, may negatively impact the fund’s performance, and may exacerbate other risks to which the fund is subject.

The values of money market investments usually rise and fall in response to changes in interest rates. Interest rate risk is generally lowest for investments with short maturities (a significant part of the fund’s investments). Changes in the financial condition of an issuer or counterparty, changes in specific economic or political conditions that affect a particular type of issuer, and changes in general economic or political conditions can increase the risk of default by an issuer or counterparty, which can affect a security’s or instrument’s credit quality or value. Certain securities in which the fund may invest, including securities issued by certain U.S. government agencies and U.S. government sponsored enterprises, are not guaranteed by the U.S. government or supported by the full faith and credit of the United States.

There is no guarantee that the investment techniques, analyses, or judgments that we apply in making investment decisions for the fund will produce the intended outcome or that the investments we select for the fund will perform as well as other securities that were not selected for the fund. We, or the fund’s other service providers, may experience disruptions or operating errors that could negatively impact the fund.

The fund may not achieve its goal, and it is not intended to be a complete investment program. You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. An investment in the fund is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The fund’s sponsor is not required to reimburse the fund for losses, and you should not expect that the sponsor will provide financial support to the fund at any time, including during periods of market stress.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class A shares. The table shows the average annual total returns of each class of the fund that has been in operation for at least one full calendar year. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ. The fund makes updated performance information, including its current net asset value, available at www.franklintempleton.com.

The fund’s past performance is not necessarily an indication of how the fund will perform in the future.

Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The accompanying bar chart and table provide some indication of the risks of investing in the fund.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress www.franklintempleton.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund’s past performance is not necessarily an indication of how the fund will perform in the future
Bar Chart [Heading] rr_BarChartHeading Annual total returns for class A shares before sales charges
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best calendar quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Sep. 30, 2024
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 1.23%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst calendar quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Mar. 31, 2022
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn none
Performance Table Heading rr_PerformanceTableHeading Average annual total returns after sales charges For periods ended 12/31/24
Prospectus 1 [Member] | Putnam Government Money Market Fund | Class A  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage) rr_MaximumDeferredSalesChargeOverOther 1.00% [1]
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.27%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none [2]
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.22%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 0.49%
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 50
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 157
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 274
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 616
Annual Return 2017 rr_AnnualReturn2017 0.30%
Annual Return 2018 rr_AnnualReturn2018 1.31%
Annual Return 2019 rr_AnnualReturn2019 1.65%
Annual Return 2020 rr_AnnualReturn2020 0.21%
Annual Return 2021 rr_AnnualReturn2021 0.01%
Annual Return 2022 rr_AnnualReturn2022 1.26%
Annual Return 2023 rr_AnnualReturn2023 4.65%
Annual Return 2024 rr_AnnualReturn2024 4.86%
1 Year rr_AverageAnnualReturnYear01 4.86%
5 Years rr_AverageAnnualReturnYear05 2.17%
Since Inception rr_AverageAnnualReturnSinceInception 1.62% [3]
Prospectus 1 [Member] | Putnam Government Money Market Fund | Class C  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage) rr_MaximumDeferredSalesChargeOverOther 1.00% [1]
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.27%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none [2]
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.22%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 0.49%
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 150
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 157
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 274
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 616
Expense Example, No Redemption, 1 Year rr_ExpenseExampleNoRedemptionYear01 50
Expense Example, No Redemption, 3 Years rr_ExpenseExampleNoRedemptionYear03 157
Expense Example, No Redemption, 5 Years rr_ExpenseExampleNoRedemptionYear05 274
Expense Example, No Redemption, 10 Years rr_ExpenseExampleNoRedemptionYear10 $ 616
1 Year rr_AverageAnnualReturnYear01 3.86% [4]
5 Years rr_AverageAnnualReturnYear05 2.17% [4]
Since Inception rr_AverageAnnualReturnSinceInception 1.62% [3],[4]
Prospectus 1 [Member] | Putnam Government Money Market Fund | Class G  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage) rr_MaximumDeferredSalesChargeOverOther none
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.27%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none [2]
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.09%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 0.36%
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 37
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 116
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 202
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 456
1 Year rr_AverageAnnualReturnYear01 5.01% [5]
5 Years rr_AverageAnnualReturnYear05 2.26% [5]
Since Inception rr_AverageAnnualReturnSinceInception 1.72% [3],[5]
Prospectus 1 [Member] | Putnam Government Money Market Fund | Class P  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage) rr_MaximumDeferredSalesChargeOverOther none
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.27%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none [2]
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.09%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 0.36%
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 37
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 116
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 202
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 456
1 Year rr_AverageAnnualReturnYear01 5.01%
5 Years rr_AverageAnnualReturnYear05 2.26%
Since Inception rr_AverageAnnualReturnSinceInception 1.72% [3]
Prospectus 1 [Member] | Putnam Government Money Market Fund | Class R  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Maximum Deferred Sales Charge (as a percentage) rr_MaximumDeferredSalesChargeOverOther none
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.27%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none [2]
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.22%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 0.49%
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 50
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 157
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 274
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 616
1 Year rr_AverageAnnualReturnYear01 4.86% [4]
5 Years rr_AverageAnnualReturnYear05 2.17% [4]
Since Inception rr_AverageAnnualReturnSinceInception 1.62% [3],[4]
Prospectus 1 [Member] | Putnam Government Money Market Fund | Risk Lose Money [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock It is important to understand that you can lose money by investing in the fund.
Prospectus 1 [Member] | Putnam Government Money Market Fund | Risk Money Market Fund Price Fluctuates [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock The values of money market investments usually rise and fall in response to changes in interest rates.
Prospectus 1 [Member] | Putnam Government Money Market Fund | Risk Not Insured Depository Institution [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock An investment in the fund is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Prospectus 1 [Member] | Putnam Government Money Market Fund | Risk Money Market Fund Sponsor May Not Provide Support [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock The fund’s sponsor is not required to reimburse the fund for losses, and you should not expect that the sponsor will provide financial support to the fund at any time, including during periods of market stress.
Prospectus 2 [Member] | Putnam Government Money Market Fund  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk/Return [Heading] rr_RiskReturnHeading Fund Summary
Objective [Heading] rr_ObjectiveHeading Goal
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks as high a rate of current income as the Investment Manager (as defined below) believes is consistent with preservation of capital and maintenance of liquidity.

Expense [Heading] rr_ExpenseHeading Fees and expenses
Expense Narrative [Text Block] rr_ExpenseNarrativeTextBlock

The following tables describe the fees and expenses you may pay if you buy, hold and sell Class I shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.

Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder fees (fees paid directly from your investment)
Operating Expenses Caption [Text] rr_OperatingExpensesCaption Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment)
Expense Example [Heading] rr_ExpenseExampleHeading Example
Expense Example, No Redemption Narrative [Text Block] rr_ExpenseExampleNoRedemptionNarrativeTextBlock

The following hypothetical example is intended to help you compare the cost of investing in the fund with the cost of investing in other funds. It assumes that you invest $10,000 in the fund for the time periods indicated and then redeem or hold all your shares at the end of those periods. It assumes a 5% return on your investment each year and that the fund’s operating expenses remain the same. Your actual costs may be higher or lower.

Strategy [Heading] rr_StrategyHeading Investments, risks, and performance
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

Investments

We invest at least 99.5 percent of the fund’s total assets in cash, U.S. government securities and repurchase agreements that are fully collateralized by U.S. government securities or cash. We invest mainly in debt securities that are obligations of the U.S. government, its agencies and instrumentalities and accordingly are backed by the full faith and credit of the United States (e.g., U.S. Treasury bills) or by the credit of a federal agency or government-sponsored entity (e.g.,securities issued by Fannie Mae and Freddie Mac). The U.S. government securities in which we invest may also include variable and floating rate instruments and when-issued and delayed delivery securities (i.e., payment or delivery of the securities occurs at a future date for a predetermined price). Under normal circumstances, we invest at least 80% of the fund’s net assets in U.S. government securities and repurchase agreements that are fully collateralized by U.S. government securities. This policy may be changed only after 60 days’ notice to shareholders. The securities purchased by the fund are subject to quality, maturity, diversification and other requirements pursuant to rules promulgated by the Securities and Exchange Commission. We may consider, among other factors, credit and interest rate risks and characteristics of the issuer or counterparty, as well as general market conditions, when deciding whether to buy or sell investments.

Risk [Heading] rr_RiskHeading Risks
Risk [Text Block] rr_RiskTextBlock

It is important to understand that you can lose money by investing in the fund.

The value of investments in the fund’s portfolio may fall or fail to rise over extended periods of time for a variety of reasons, including general economic, political or financial market conditions, investor sentiment and market perceptions, government actions, geopolitical events or changes, outbreaks of infectious illnesses or other widespread public health issues, and factors related to a specific issuer, asset class, geography, industry or sector. These and other factors may lead to increased volatility and reduced liquidity in the fund’s portfolio holdings, may negatively impact the fund’s performance, and may exacerbate other risks to which the fund is subject.

The values of money market investments usually rise and fall in response to changes in interest rates. Interest rate risk is generally lowest for investments with short maturities (a significant part of the fund’s investments). Changes in the financial condition of an issuer or counterparty, changes in specific economic or political conditions that affect a particular type of issuer, and changes in general economic or political conditions can increase the risk of default by an issuer or counterparty, which can affect a security’s or instrument’s credit quality or value. Certain securities in which the fund may invest, including securities issued by certain U.S. government agencies and U.S. government sponsored enterprises, are not guaranteed by the U.S. government or supported by the full faith and credit of the United States.

There is no guarantee that the investment techniques, analyses, or judgments that we apply in making investment decisions for the fund will produce the intended outcome or that the investments we select for the fund will perform as well as other securities that were not selected for the fund. We, or the fund’s other service providers, may experience disruptions or operating errors that could negatively impact the fund.

The fund may not achieve its goal, and it is not intended to be a complete investment program. You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. An investment in the fund is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The fund’s sponsor is not required to reimburse the fund for losses, and you should not expect that the sponsor will provide financial support to the fund at any time, including during periods of market stress.

Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The accompanying bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Class I shares. The table shows the average annual total returns of Class I shares. Performance for classes other than those shown may vary from the performance shown to the extent the expenses for those classes differ.

The fund’s past performance is not necessarily an indication of how the fund will perform in the future.

Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The accompanying bar chart and table provide some indication of the risks of investing in the fund
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund’s past performance is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] rr_BarChartHeading Annual total returns for class I shares before sales charges
Highest Quarterly Return, Label rr_HighestQuarterlyReturnLabel Best calendar quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Dec. 31, 2023
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 1.27%
Lowest Quarterly Return, Label rr_LowestQuarterlyReturnLabel Worst calendar quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Mar. 31, 2022
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn none
Performance Table Heading rr_PerformanceTableHeading Average annual total returns after sales charges For periods ended 12/31/24
Prospectus 2 [Member] | Putnam Government Money Market Fund | Class I  
Prospectus [Line Items] rr_ProspectusLineItems  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice none
Management Fees (as a percentage of Assets) rr_ManagementFeesOverAssets 0.27%
Distribution and Service (12b-1) Fees rr_DistributionAndService12b1FeesOverAssets none
Other Expenses (as a percentage of Assets): rr_OtherExpensesOverAssets 0.09%
Expenses (as a percentage of Assets) rr_ExpensesOverAssets 0.36%
Expense Example, with Redemption, 1 Year rr_ExpenseExampleYear01 $ 37
Expense Example, with Redemption, 3 Years rr_ExpenseExampleYear03 116
Expense Example, with Redemption, 5 Years rr_ExpenseExampleYear05 202
Expense Example, with Redemption, 10 Years rr_ExpenseExampleYear10 $ 456
Annual Return 2017 rr_AnnualReturn2017 0.43%
Annual Return 2018 rr_AnnualReturn2018 1.47%
Annual Return 2019 rr_AnnualReturn2019 1.82%
Annual Return 2020 rr_AnnualReturn2020 0.25%
Annual Return 2021 rr_AnnualReturn2021 0.01%
Annual Return 2022 rr_AnnualReturn2022 1.35%
Annual Return 2023 rr_AnnualReturn2023 4.79%
Annual Return 2024 rr_AnnualReturn2024 5.01%
1 Year rr_AverageAnnualReturnYear01 5.01%
5 Years rr_AverageAnnualReturnYear05 2.26%
Since Inception rr_AverageAnnualReturnSinceInception 1.72% [6]
Prospectus 2 [Member] | Putnam Government Money Market Fund | Risk Lose Money [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock It is important to understand that you can lose money by investing in the fund.
Prospectus 2 [Member] | Putnam Government Money Market Fund | Risk Money Market Fund Price Fluctuates [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock The values of money market investments usually rise and fall in response to changes in interest rates
Prospectus 2 [Member] | Putnam Government Money Market Fund | Risk Not Insured Depository Institution [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock An investment in the fund is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Prospectus 2 [Member] | Putnam Government Money Market Fund | Risk Money Market Fund Sponsor May Not Provide Support [Member]  
Prospectus [Line Items] rr_ProspectusLineItems  
Risk [Text Block] rr_RiskTextBlock The fund’s sponsor is not required to reimburse the fund for losses, and you should not expect that the sponsor will provide financial support to the fund at any time, including during periods of market stress.
[1] A deferred sales charge on class A and C shares may apply to certain redemptions of shares purchased by exchange from another Putnam fund. The rate of the deferred sales charge for class C shares will be determined based on the time between the original purchase of class C shares from the other Putnam fund(s) and date of redemption of shares from this fund.
[2] The fund’s Board of Trustees has determined to limit payments under the distribution and services (12b-1) plans in place with respect to class C and class R shares to 0.00% of average net assets.
[3] Since inception April 14, 2016.
[4] Performance for class C and R shares before their inception (6/16/16) is derived from the historical performance of class A shares, adjusted for the applicable sales charge (or CDSC) and the expense waiver in effect at that time.
[5] Performance for class G shares before their inception (8/30/16) is derived from the historical performance of class A shares, adjusted for the applicable sales charge (or CDSC) and the expense waiver in effect at that time. Class G shares had no assets or operations for the period from February 11, 2023 through September 10, 2023. The performance shown for class G shares for this period is derived from the historical performance of class P shares, which bear similar fees and expenses.
[6] Since inception April 14, 2016.