v3.26.1
Label Element Value
Prospectus Summary | Dreyfus Money Market Fund  
Risk/Return: oef_RiskReturnAbstract  
Risk/Return [Heading] oef_RiskReturnHeading Fund Summary
Objective [Heading] oef_ObjectiveHeading Investment Objective
Objective, Primary [Text Block] oef_ObjectivePrimaryTextBlock The fund seeks as high a level of current income as is consistent with the preservation of capital.
Expense Heading [Optional Text] oef_ExpenseHeading Fees and Expenses
Expense Narrative [Text Block] oef_ExpenseNarrativeTextBlock

This table describes the fees and expenses that 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 table and examples below.

Operating Expenses Caption [Optional Text] oef_OperatingExpensesCaption Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Expense Example [Heading] oef_ExpenseExampleHeading Example
Expense Example Narrative [Text Block] oef_ExpenseExampleNarrativeTextBlock

The Example is intended to help you compare the cost of investing in the fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the fund for the time periods indicated and then hold or redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Strategy [Heading] oef_StrategyHeading Principal Investment Strategy
Strategy Narrative [Text Block] oef_StrategyNarrativeTextBlock

To pursue its goal, the fund normally invests in a diversified portfolio of high quality, short-term, dollar-denominated debt securities, including: securities issued or guaranteed as to principal and interest by the U.S. government or its agencies or instrumentalities; certificates of deposit, time deposits, bankers' acceptances and other short-term securities issued by domestic or foreign banks or thrifts or their subsidiaries or branches; repurchase agreements, including tri-party repurchase agreements; asset-backed securities; domestic and dollar-denominated foreign commercial paper and other short-term corporate obligations, including those with floating or variable rates of interest; and dollar-denominated obligations issued or guaranteed by one or more foreign governments or any of their political subdivisions or agencies. The fund's investments are concentrated in the banking industry, because the fund normally invests at least 25% of its assets in domestic or dollar-denominated foreign bank obligations.

The fund is a money market fund subject to the maturity, quality, liquidity and diversification requirements of Rule 2a-7 under the Investment Company Act of 1940, as amended, and seeks to maintain a stable share price of $1.00.

 
Bar Chart and Performance Table [Heading] oef_BarChartAndPerformanceTableHeading Performance
Performance Narrative [Text Block] oef_PerformanceNarrativeTextBlock

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the performance of the fund's Premier shares from year to year. The table shows the average annual total returns of the fund's Premier shares over time. The fund's past performance is not necessarily an indication of how the fund will perform in the future. More recent performance information may be available at www.dreyfus.com.

Performance Information Illustrates Variability of Returns [Text] oef_PerformanceInformationIllustratesVariabilityOfReturns The following bar chart and table provide some indication of the risks of investing in the fund.
Performance Availability Website Address [Text] oef_PerformanceAvailabilityWebSiteAddress www.dreyfus.com
Performance Past Does Not Indicate Future [Text] oef_PerformancePastDoesNotIndicateFuture The fund's past performance is not necessarily an indication of how the fund will perform in the future.
Bar Chart [Heading] oef_BarChartHeading Year-by-Year Total Returns as of 12/31 each year (%)
Bar Chart Closing [Text Block] oef_BarChartClosingTextBlock

During the periods shown in the chart:
Best Quarter
2023, Q4: 1.35
Worst Quarter
2021, Q4: 0.00

Performance Table Closing [Text Block] oef_PerformanceTableClosingTextBlock For the fund's current yield for Premier shares, call toll-free 1-800-373-9387 (inside the U.S. only).
Average Annual Return, Caption [Optional Text] oef_AverageAnnualReturnCaption Average Annual Total Returns as of 12/31/25
Money Market Seven Day Yield Phone oef_MoneyMarketSevenDayYieldPhone 1-800-373-9387
Prospectus Summary | Dreyfus Money Market Fund | Principal Risks  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock
Principal Risks

An investment in the fund is not a bank account or a bank deposit. It is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency. 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. The fund may impose a fee upon the sale of your shares. The fund's yield will fluctuate as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in securities with different interest rates. BNY Mellon Investment Adviser, Inc. and its affiliates are not required to reimburse the fund for losses, and you should not expect that BNY Mellon Investment Adviser, Inc. or its affiliates will provide financial support to the fund at any time, including during periods of market stress. The following are the principal risks that could reduce the fund's income level and/or share price:

Prospectus Summary | Dreyfus Money Market Fund | Risk Lose Money [Member]  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock You could lose money by investing in the fund.
Prospectus Summary | Dreyfus Money Market Fund | Risk Money Market Fund Price Fluctuates [Member]  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock The fund's yield will fluctuate as the short-term securities in its portfolio mature or are sold and the proceeds are reinvested in securities with different interest rates.
Prospectus Summary | Dreyfus Money Market Fund | Risk Money Market Fund May Not Preserve Dollar [Member]  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so.
Prospectus Summary | Dreyfus Money Market Fund | Risk Not Insured [Member]  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock An investment in the fund is not a bank account or a bank deposit. It is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
Prospectus Summary | Dreyfus Money Market Fund | · Interest rate risk  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

· Interest rate risk: This risk refers to the decline in the prices of fixed-income securities that may accompany a rise in the overall level of interest rates. A sharp and unexpected rise in interest rates could impair the fund's ability to maintain a stable net asset value. A wide variety of market factors can cause interest rates to rise, including central bank monetary policy, rising inflation and changes in general economic conditions. It is difficult to predict the pace at which central banks or monetary authorities may increase (or decrease) interest rates or the timing, frequency, or magnitude of such changes. Changing interest rates may have unpredictable effects on markets, may result in heightened market volatility and may detract from fund performance. For floating and variable rate obligations, there may be a lag between an actual change in the underlying interest rate benchmark and the reset time for an interest payment of such an obligation, which could harm or benefit the fund, depending on the interest rate environment or other circumstances.

Prospectus Summary | Dreyfus Money Market Fund | · Liquidity risk  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

· Liquidity risk: When there is little or no active trading market for specific types of securities, it can become more difficult to sell the securities in a timely manner at or near their perceived value. In such a market, the value of such securities may fall dramatically, potentially impairing the fund's ability to maintain a stable net asset value.

Prospectus Summary | Dreyfus Money Market Fund | · Credit risk  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

· Credit risk: Failure of an issuer of a security to make timely interest or principal payments when due, or a decline or perception of a decline in the credit quality of the security, can cause the security's price to fall. Although the fund invests only in high quality debt securities, the credit quality of the securities held by the fund can change rapidly in certain market environments, and the default or a significant price decline of a single holding could impair the fund's ability to maintain a stable net asset value.

Prospectus Summary | Dreyfus Money Market Fund | · Liquidity fee risk  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

· Liquidity fee risk: The fund may impose a discretionary liquidity fee upon the redemption of fund shares if such a fee is determined to be in the best interests of the fund. The fund's board has delegated to Dreyfus the responsibility to make liquidity fee determinations pursuant to board-approved written guidelines. If a discretionary liquidity fee is imposed by the fund, it would reduce the amount a redeeming shareholder would receive upon the sale of fund shares during the period the fee is in effect. If the fund imposes a discretionary liquidity fee, it is possible that it may return the fee to shareholders in the form of a distribution at a later time.

Prospectus Summary | Dreyfus Money Market Fund | · Banking industry risk  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

· Banking industry risk: The risks generally associated with concentrating investments (i.e., hold 25% or more of its total assets) in the banking industry include interest rate risk, credit risk, and regulatory developments relating to the banking industry. Banks may be particularly susceptible to certain economic factors such as interest rate changes, adverse developments in the real estate market, fiscal and monetary policy and general economic cycles. An adverse development in the banking industry (domestic or foreign) may affect the value of the fund's investments more than if such investments were not concentrated in the banking industry.

Prospectus Summary | Dreyfus Money Market Fund | · Foreign investment risk  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

· Foreign investment risk: The risks generally associated with dollar-denominated foreign investments include economic and political developments, seizure or nationalization of deposits, imposition of taxes or other restrictions on payment of principal and interest. The imposition of sanctions, confiscations, trade restrictions (including tariffs) and other government restrictions by the United States and other governments, or from problems in share registration, settlement or custody, may also result in losses. In addition, the fund will be subject to the risk that an issuer of foreign sovereign debt or the government authorities that control the repayment of the debt may be unable or unwilling to repay the principal or interest when due.

Prospectus Summary | Dreyfus Money Market Fund | · U.S. Treasury securities risk  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

· U.S. Treasury securities risk: A security backed by the U.S. Treasury or the full faith and credit of the United States is guaranteed only as to the timely payment of interest and principal when held to maturity, but the market prices for such securities are not guaranteed and will fluctuate.

Prospectus Summary | Dreyfus Money Market Fund | · Government securities risk  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

· Government securities risk: Not all obligations of the U.S. government, its agencies and instrumentalities are backed by the full faith and credit of the U.S. Treasury. Some obligations are backed only by the credit of the issuing agency or instrumentality, and in some cases there may be some risk of default by the issuer. Any guarantee by the U.S. government or its agencies or instrumentalities of a security held by the fund does not apply to the market value of such security or to shares of the fund itself.

Prospectus Summary | Dreyfus Money Market Fund | · Repurchase agreement counterparty risk  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

· Repurchase agreement counterparty risk: The fund is subject to the risk that a counterparty in a repurchase agreement and/or, for a tri-party repurchase agreement, the third party bank providing payment administration, collateral custody and management services for the transaction, could fail to honor the terms of the agreement. If this occurs, the fund may suffer a loss if the proceeds from the sale of the underlying securities are less than the repurchase price.

Prospectus Summary | Dreyfus Money Market Fund | · Asset-backed securities risk  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

· Asset-backed securities risk: Asset-backed securities are subject to credit, prepayment and extension risk, and may be more volatile, less liquid and more difficult to price accurately than more traditional debt securities. General downturns in the economy could cause the value of asset-backed securities to fall. Asset-backed securities are often subject to more rapid repayment than their stated maturity date would indicate as a result of the pass-through of prepayments of principal on the underlying loans.

Prospectus Summary | Dreyfus Money Market Fund | · Market risk  
Risk/Return: oef_RiskReturnAbstract  
Risk [Text Block] oef_RiskTextBlock

· Market risk: The value of the securities in which the fund invests may be affected by political, regulatory, economic and social developments.  In addition, turbulence in financial markets and reduced liquidity in fixed-income markets may negatively affect many issuers, which could adversely affect the fund. Global economies and financial markets are becoming increasingly interconnected, and conditions and events in one country, region or financial market may adversely impact issuers in a different country, region or financial market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain; in these and other circumstances, such risks might affect companies world-wide. Local, regional or global events such as war, acts of terrorism, natural disasters, the spread of infectious illness or other public health issues, recessions, elevated levels of government debt, changes in trade regulation or economic sanctions, internal unrest and discord, or other events could have a significant impact on the fund and its investments.

Prospectus Summary | Dreyfus Money Market Fund | Premier Shares  
Risk/Return: oef_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol GMGXX
Management Fees (as a percentage of Assets) oef_ManagementFeesOverAssets 0.20%
Component2 Other Expenses oef_Component2OtherExpensesOverAssets 0.03%
Component3 Other Expenses oef_Component3OtherExpensesOverAssets 0.04%
Other Expenses (as a percentage of Assets): oef_OtherExpensesOverAssets 0.07%
Expenses (as a percentage of Assets) oef_ExpensesOverAssets 0.27%
Expense Example, with Redemption, 1 Year oef_ExpenseExampleYear01 $ 28
Expense Example, with Redemption, 3 Years oef_ExpenseExampleYear03 87
Expense Example, with Redemption, 5 Years oef_ExpenseExampleYear05 152
Expense Example, with Redemption, 10 Years oef_ExpenseExampleYear10 $ 343
Highest Quarterly Return, Label [Optional Text] oef_HighestQuarterlyReturnLabel Best Quarter
Highest Quarterly Return, Date oef_BarChartHighestQuarterlyReturnDate Dec. 31, 2023
Highest Quarterly Return oef_BarChartHighestQuarterlyReturn 1.35%
Lowest Quarterly Return, Label [Optional Text] oef_LowestQuarterlyReturnLabel Worst Quarter
Lowest Quarterly Return, Date oef_BarChartLowestQuarterlyReturnDate Dec. 31, 2021
Lowest Quarterly Return oef_BarChartLowestQuarterlyReturn none
Average Annual Return, Percent oef_AvgAnnlRtrPct 4.26%
Average Annual Return, Percent oef_AvgAnnlRtrPct 3.21%
Average Annual Return, Percent oef_AvgAnnlRtrPct 2.02%
Annual Return [Percent] oef_AnnlRtrPct 0.04%
Annual Return [Percent] oef_AnnlRtrPct 0.56%
Annual Return [Percent] oef_AnnlRtrPct 1.53%
Annual Return [Percent] oef_AnnlRtrPct 1.82%
Annual Return [Percent] oef_AnnlRtrPct 0.26%
Annual Return [Percent] oef_AnnlRtrPct 0.01%
Annual Return [Percent] oef_AnnlRtrPct 1.59%
Annual Return [Percent] oef_AnnlRtrPct 5.10%
Annual Return [Percent] oef_AnnlRtrPct 5.20%
Annual Return [Percent] oef_AnnlRtrPct 4.26%