<?xml version="1.0" encoding="utf-8"?>
<FilingSummary xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <Version>2.4.0.6</Version>
  <ProcessingTime />
  <ReportFormat>Html</ReportFormat>
  <ContextCount>25</ContextCount>
  <ElementCount>65</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>30</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>2</UnitCount>
  <MyReports>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>000001 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>true</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>020000 - Document - Risk/Return Summary {Unlabeled} - GENERAL MONEY MARKET FUND INC (Class A)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DocumentRiskReturnSummaryUnlabeledGENERALMONEYMARKETFUNDINCClassA</Role>
      <ShortName>Risk/Return Summary  - GENERAL MONEY MARKET FUND INC (Class A)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>020005 - Disclosure - Risk/Return Detail Data {Elements} - GENERAL MONEY MARKET FUND INC (Class A)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DisclosureRiskReturnDetailDataElementsGENERALMONEYMARKETFUNDINCClassA</Role>
      <ShortName>Risk/Return Detail Data  - GENERAL MONEY MARKET FUND INC (Class A)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>true</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>020006 - Document - Risk/Return Summary {Unlabeled} - General Government Securities Money Market Fund (Class A)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DocumentRiskReturnSummaryUnlabeledGeneralGovernmentSecuritiesMoneyMarketFundClassA</Role>
      <ShortName>Risk/Return Summary  - General Government Securities Money Market Fund (Class A)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>020011 - Disclosure - Risk/Return Detail Data {Elements} - General Government Securities Money Market Fund (Class A)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DisclosureRiskReturnDetailDataElementsGeneralGovernmentSecuritiesMoneyMarketFundClassA</Role>
      <ShortName>Risk/Return Detail Data  - General Government Securities Money Market Fund (Class A)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>true</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>020012 - Document - Risk/Return Summary {Unlabeled} - General Treasury Prime Money Market Fund (Class A)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DocumentRiskReturnSummaryUnlabeledGeneralTreasuryPrimeMoneyMarketFundClassA</Role>
      <ShortName>Risk/Return Summary  - General Treasury Prime Money Market Fund (Class A)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>020017 - Disclosure - Risk/Return Detail Data {Elements} - General Treasury Prime Money Market Fund (Class A)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DisclosureRiskReturnDetailDataElementsGeneralTreasuryPrimeMoneyMarketFundClassA</Role>
      <ShortName>Risk/Return Detail Data  - General Treasury Prime Money Market Fund (Class A)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>true</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>020018 - Document - Risk/Return Summary {Unlabeled} - General Municipal Money Market Funds, Inc. (General Municipal Money Market Fund - Class A)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DocumentRiskReturnSummaryUnlabeledGeneralMunicipalMoneyMarketFundsIncGeneralMunicipalMoneyMarketFundClassA</Role>
      <ShortName>Risk/Return Summary  - General Municipal Money Market Funds, Inc. (General Municipal Money Market Fund - Class A)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>020023 - Disclosure - Risk/Return Detail Data {Elements} - General Municipal Money Market Funds, Inc. (General Municipal Money Market Fund - Class A)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DisclosureRiskReturnDetailDataElementsGeneralMunicipalMoneyMarketFundsIncGeneralMunicipalMoneyMarketFundClassA</Role>
      <ShortName>Risk/Return Detail Data  - General Municipal Money Market Funds, Inc. (General Municipal Money Market Fund - Class A)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>true</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>020024 - Document - Risk/Return Summary {Unlabeled} - GENERAL CALIFORNIA MUNICIPAL MONEY MARKET FUND (Class A)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DocumentRiskReturnSummaryUnlabeledGENERALCALIFORNIAMUNICIPALMONEYMARKETFUNDClassA</Role>
      <ShortName>Risk/Return Summary  - GENERAL CALIFORNIA MUNICIPAL MONEY MARKET FUND (Class A)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>020029 - Disclosure - Risk/Return Detail Data {Elements} - GENERAL CALIFORNIA MUNICIPAL MONEY MARKET FUND (Class A)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DisclosureRiskReturnDetailDataElementsGENERALCALIFORNIAMUNICIPALMONEYMARKETFUNDClassA</Role>
      <ShortName>Risk/Return Detail Data  - GENERAL CALIFORNIA MUNICIPAL MONEY MARKET FUND (Class A)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>true</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>020030 - Document - Risk/Return Summary {Unlabeled} - GENERAL NEW YORK MUNICIPAL MONEY MARKET FUND (Class A)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DocumentRiskReturnSummaryUnlabeledGENERALNEWYORKMUNICIPALMONEYMARKETFUNDClassA</Role>
      <ShortName>Risk/Return Summary  - GENERAL NEW YORK MUNICIPAL MONEY MARKET FUND (Class A)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>020035 - Disclosure - Risk/Return Detail Data {Elements} - GENERAL NEW YORK MUNICIPAL MONEY MARKET FUND (Class A)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DisclosureRiskReturnDetailDataElementsGENERALNEWYORKMUNICIPALMONEYMARKETFUNDClassA</Role>
      <ShortName>Risk/Return Detail Data  - GENERAL NEW YORK MUNICIPAL MONEY MARKET FUND (Class A)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>true</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>020036 - Document - Risk/Return Summary {Unlabeled} - GENERAL MONEY MARKET FUND INC (Class B)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DocumentRiskReturnSummaryUnlabeledGENERALMONEYMARKETFUNDINCClassB</Role>
      <ShortName>Risk/Return Summary  - GENERAL MONEY MARKET FUND INC (Class B)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>020041 - Disclosure - Risk/Return Detail Data {Elements} - GENERAL MONEY MARKET FUND INC (Class B)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DisclosureRiskReturnDetailDataElementsGENERALMONEYMARKETFUNDINCClassB</Role>
      <ShortName>Risk/Return Detail Data  - GENERAL MONEY MARKET FUND INC (Class B)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>true</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>020042 - Document - Risk/Return Summary {Unlabeled} - General Government Securities Money Market Fund (Class B)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DocumentRiskReturnSummaryUnlabeledGeneralGovernmentSecuritiesMoneyMarketFundClassB</Role>
      <ShortName>Risk/Return Summary  - General Government Securities Money Market Fund (Class B)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R49.htm</HtmlFileName>
      <LongName>020047 - Disclosure - Risk/Return Detail Data {Elements} - General Government Securities Money Market Fund (Class B)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DisclosureRiskReturnDetailDataElementsGeneralGovernmentSecuritiesMoneyMarketFundClassB</Role>
      <ShortName>Risk/Return Detail Data  - General Government Securities Money Market Fund (Class B)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>true</HasEmbeddedReports>
      <HtmlFileName>R50.htm</HtmlFileName>
      <LongName>020048 - Document - Risk/Return Summary {Unlabeled} - General Treasury Prime Money Market Fund (Class B)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DocumentRiskReturnSummaryUnlabeledGeneralTreasuryPrimeMoneyMarketFundClassB</Role>
      <ShortName>Risk/Return Summary  - General Treasury Prime Money Market Fund (Class B)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R55.htm</HtmlFileName>
      <LongName>020053 - Disclosure - Risk/Return Detail Data {Elements} - General Treasury Prime Money Market Fund (Class B)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DisclosureRiskReturnDetailDataElementsGeneralTreasuryPrimeMoneyMarketFundClassB</Role>
      <ShortName>Risk/Return Detail Data  - General Treasury Prime Money Market Fund (Class B)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>true</HasEmbeddedReports>
      <HtmlFileName>R56.htm</HtmlFileName>
      <LongName>020054 - Document - Risk/Return Summary {Unlabeled} - General Municipal Money Market Funds, Inc. (General Municipal Money Market Fund - Class B)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DocumentRiskReturnSummaryUnlabeledGeneralMunicipalMoneyMarketFundsIncGeneralMunicipalMoneyMarketFundClassB</Role>
      <ShortName>Risk/Return Summary  - General Municipal Money Market Funds, Inc. (General Municipal Money Market Fund - Class B)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R61.htm</HtmlFileName>
      <LongName>020059 - Disclosure - Risk/Return Detail Data {Elements} - General Municipal Money Market Funds, Inc. (General Municipal Money Market Fund - Class B)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DisclosureRiskReturnDetailDataElementsGeneralMunicipalMoneyMarketFundsIncGeneralMunicipalMoneyMarketFundClassB</Role>
      <ShortName>Risk/Return Detail Data  - General Municipal Money Market Funds, Inc. (General Municipal Money Market Fund - Class B)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>true</HasEmbeddedReports>
      <HtmlFileName>R62.htm</HtmlFileName>
      <LongName>020060 - Document - Risk/Return Summary {Unlabeled} - GENERAL CALIFORNIA MUNICIPAL MONEY MARKET FUND (Class B)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DocumentRiskReturnSummaryUnlabeledGENERALCALIFORNIAMUNICIPALMONEYMARKETFUNDClassB</Role>
      <ShortName>Risk/Return Summary  - GENERAL CALIFORNIA MUNICIPAL MONEY MARKET FUND (Class B)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R67.htm</HtmlFileName>
      <LongName>020065 - Disclosure - Risk/Return Detail Data {Elements} - GENERAL CALIFORNIA MUNICIPAL MONEY MARKET FUND (Class B)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DisclosureRiskReturnDetailDataElementsGENERALCALIFORNIAMUNICIPALMONEYMARKETFUNDClassB</Role>
      <ShortName>Risk/Return Detail Data  - GENERAL CALIFORNIA MUNICIPAL MONEY MARKET FUND (Class B)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>true</HasEmbeddedReports>
      <HtmlFileName>R68.htm</HtmlFileName>
      <LongName>020066 - Document - Risk/Return Summary {Unlabeled} - GENERAL NEW YORK MUNICIPAL MONEY MARKET FUND (Class B)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DocumentRiskReturnSummaryUnlabeledGENERALNEWYORKMUNICIPALMONEYMARKETFUNDClassB</Role>
      <ShortName>Risk/Return Summary  - GENERAL NEW YORK MUNICIPAL MONEY MARKET FUND (Class B)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R73.htm</HtmlFileName>
      <LongName>020071 - Disclosure - Risk/Return Detail Data {Elements} - GENERAL NEW YORK MUNICIPAL MONEY MARKET FUND (Class B)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://dreyfus.com/20130328/role/DisclosureRiskReturnDetailDataElementsGENERALNEWYORKMUNICIPALMONEYMARKETFUNDClassB</Role>
      <ShortName>Risk/Return Detail Data  - GENERAL NEW YORK MUNICIPAL MONEY MARKET FUND (Class B)</ShortName>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R74.htm</HtmlFileName>
      <LongName>040000 - Disclosure - Risk/Return Detail Data {Elements}</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://xbrl.sec.gov/rr/role/RiskReturnDetailData</Role>
      <ShortName>Risk/Return Detail Data</ShortName>
    </Report>
    <Report>
      <IsDefault>true</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <Logs />
  <InputFiles>
    <File>ck0000703153-20130328.xml</File>
    <File>ck0000703153-20130328.xsd</File>
    <File>ck0000703153-20130328_cal.xml</File>
    <File>ck0000703153-20130328_def.xml</File>
    <File>ck0000703153-20130328_lab.xml</File>
    <File>ck0000703153-20130328_pre.xml</File>
  </InputFiles>
  <SupplementalFiles>
    <File>BarChart1.jpg</File>
    <File>BarChart2.jpg</File>
    <File>BarChart3.jpg</File>
    <File>BarChart4.jpg</File>
    <File>BarChart5.jpg</File>
    <File>BarChart6.jpg</File>
    <File>BarChart7.jpg</File>
    <File>BarChart8.jpg</File>
    <File>BarChart9.jpg</File>
    <File>BarChart10.jpg</File>
    <File>BarChart11.jpg</File>
    <File>BarChart12.jpg</File>
  </SupplementalFiles>
  <BaseTaxonomies />
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
