Label	Element	Value
Dreyfus Class Prospectus \| General Government Securities Money Market Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Fund Summary - General Government Securities Money Market Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The fund seeks as high a level of current income as is consistent with the preservation of capital and maintenance of liquidity.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the fund.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (expenses that 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 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 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]	rr_StrategyHeading	Principal Investment Strategy
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	As a money market fund, the fund is subject to the maturity, quality, liquidity and diversification requirements of Rule 2a-7 under the Investment Company Act of 1940, as amended, which are designed to help money market funds maintain a stable share price of $1.00. To pursue its goal, the fund invests at least 99.5% of its total assets in securities issued or guaranteed as to principal and interest by the U.S. government or its agencies or instrumentalities, including those with floating or variable rates of interest, repurchase agreements (including tri-party repurchase agreements) in respect of such securities and cash. The securities in which the fund invests include those backed by the full faith and credit of the U.S. government and those that are neither insured nor guaranteed by the U.S. government.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	An investment in the fund is not a bank deposit. An investment in the fund 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. Neither The Dreyfus Corporation nor its affiliates has a legal obligation to provide financial support to the fund, and you should not expect that The Dreyfus Corporation or its affiliates will provide financial support to the fund at any time. The fund's yield will fluctuate as the short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates. The following are the principal risks that could reduce the fund's income level and/or share price: · 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 cause a money market fund's shareprice to drop below a dollar. A low interest rate environment may prevent the fund from providing a positive yield or paying fund expenses out of fund assets and could impair the fund's ability to maintain a stable net asset value. · 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, even during periods of declining interest rates. · 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. In addition, because many types of U.S. government securities trade actively outside the United States, their prices may rise and fall as changes in global economic conditions affect the demand for these securities. · 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 price for such securities are not guaranteed and will fluctuate. · Repurchase agreement counterparty risk. The risk that a counterparty in a repurchase agreement could fail to honor the terms of its agreement.
Risk Money Market Fund [Text]	rr_RiskMoneyMarketFund	Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	An investment in the fund is not a bank deposit. An investment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance
Performance Narrative [Text Block]	rr_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 Class A shares from year to year. The table shows the average annual total returns of the fund's Class A 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. Since the fund's Dreyfus Class shares are new, past performance information is not available for Dreyfus Class shares as of the date of this prospectus. Dreyfus Class shares would have had substantially similar annual returns as Class A shares because each share class is invested in the same portfolio of securities and the annual returns would have differed only to the extent that the classes do not have the same expenses.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The following bar chart and table provide some indication of the risks of investing in the fund.
Performance One Year or Less [Text]	rr_PerformanceOneYearOrLess	Since the fund's Dreyfus Class shares are new, past performance information is not available for Dreyfus Class shares as of the date of this prospectus.
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.dreyfus.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	Year-by-Year Total Returns as of 12/31 each year (%) Class A
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	Best Quarter Q4, 2006: 1.14% Worst Quarter Q3, 2015: 0.00% The total return of the fund's Class A shares for the first quarter of the fund's fiscal year (December 1, 2015 through February 29, 2016) was 0.00%.
Bar Chart, Returns for Class Not Offered in Prospectus [Text]	rr_BarChartReturnsForClassNotOfferedInProspectus	The bar chart shows changes in the performance of the fund's Class A shares from year to year.
Year to Date Return, Label	rr_YearToDateReturnLabel	total return
Bar Chart, Year to Date Return, Date	rr_BarChartYearToDateReturnDate	Feb. 29, 2016
Bar Chart, Year to Date Return	rr_BarChartYearToDateReturn	none
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	Best Quarter
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Dec. 31, 2006
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	1.14%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	Worst Quarter
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2015
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	none
Performance Table Closing [Text Block]	rr_PerformanceTableClosingTextBlock	For the fund’s current yield, call toll free 1-800-DREYFUS (inside the U.S. only).
Caption	rr_AverageAnnualReturnCaption	Average Annual Total Returns as of 12/31/15
Money Market Seven Day Yield Phone	rr_MoneyMarketSevenDayYieldPhone	1-800-DREYFUS
Dreyfus Class Prospectus \| General Government Securities Money Market Fund \| Dreyfus Class
Risk/Return:	rr_RiskReturnAbstract
Management fees	rr_ManagementFeesOverAssets	0.50%
Other expenses (including shareholder services fees)	rr_OtherExpensesOverAssets	0.05%
Total annual fund operating expenses	rr_ExpensesOverAssets	0.55%
Expense Example, with Redemption, 1 Year	rr_ExpenseExampleYear01	$ 56
Expense Example, with Redemption, 3 Years	rr_ExpenseExampleYear03	176
Expense Example, with Redemption, 5 Years	rr_ExpenseExampleYear05	307
Expense Example, with Redemption, 10 Years	rr_ExpenseExampleYear10	$ 689
Dreyfus Class Prospectus \| General Government Securities Money Market Fund \| Class A
Risk/Return:	rr_RiskReturnAbstract
Annual Return 2006	rr_AnnualReturn2006	4.26%
Annual Return 2007	rr_AnnualReturn2007	4.36%
Annual Return 2008	rr_AnnualReturn2008	1.72%
Annual Return 2009	rr_AnnualReturn2009	0.02%
Annual Return 2010	rr_AnnualReturn2010	none
Annual Return 2011	rr_AnnualReturn2011	none
Annual Return 2012	rr_AnnualReturn2012	none
Annual Return 2013	rr_AnnualReturn2013	none
Annual Return 2014	rr_AnnualReturn2014	none
Annual Return 2015	rr_AnnualReturn2015	none
Average Annual Returns, 1 Year	rr_AverageAnnualReturnYear01	none
Average Annual Returns, 5 Years	rr_AverageAnnualReturnYear05	none
Average Annual Returns, 10 Years	rr_AverageAnnualReturnYear10	1.02%

If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 4
-Subsection b
-Paragraph 2
-Subparagraph ii