3.5.0.1 html 81 70 1 false 54 0 false 2 false false R1.htm 000001 - Document - Document and Entity Information Sheet http://dreyfus.com/20160527/role/DocumentAndEntityInformation Document and Entity Information 1 false true R2.htm 020000 - Document - Risk/Return Summary {Unlabeled} - Administrative Shares Prospectus - Dreyfus Cash Management (administrative shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledAdministrativeSharesProspectusDreyfusCashManagementadministrativeshares Risk/Return Summary- Administrative Shares Prospectus - Dreyfus Cash Management (administrative shares) 2 false false R7.htm 020005 - Disclosure - Risk/Return Detail Data {Elements} - Administrative Shares Prospectus - Dreyfus Cash Management (administrative shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsAdministrativeSharesProspectusDreyfusCashManagementadministrativeshares Risk/Return Detail Data- Administrative Shares Prospectus - Dreyfus Cash Management (administrative shares) 3 false true R8.htm 020006 - Document - Risk/Return Summary {Unlabeled} - Administrative Shares Prospectus - Dreyfus Government Cash Management (dreyfus government cash management - Administrative Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledAdministrativeSharesProspectusDreyfusGovernmentCashManagementdreyfusgovernmentcashmanagementAdministrativeShares Risk/Return Summary- Administrative Shares Prospectus - Dreyfus Government Cash Management (dreyfus government cash management - Administrative Shares) 4 false false R13.htm 020011 - Disclosure - Risk/Return Detail Data {Elements} - Administrative Shares Prospectus - Dreyfus Government Cash Management (dreyfus government cash management - Administrative Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsAdministrativeSharesProspectusDreyfusGovernmentCashManagementdreyfusgovernmentcashmanagementAdministrativeShares Risk/Return Detail Data- Administrative Shares Prospectus - Dreyfus Government Cash Management (dreyfus government cash management - Administrative Shares) 5 false true R14.htm 020012 - Document - Risk/Return Summary {Unlabeled} - Administrative Shares Prospectus - Dreyfus Government Securities Cash Management (- Administrative Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledAdministrativeSharesProspectusDreyfusGovernmentSecuritiesCashManagementAdministrativeShares Risk/Return Summary- Administrative Shares Prospectus - Dreyfus Government Securities Cash Management (- Administrative Shares) 6 false false R19.htm 020017 - Disclosure - Risk/Return Detail Data {Elements} - Administrative Shares Prospectus - Dreyfus Government Securities Cash Management (- Administrative Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsAdministrativeSharesProspectusDreyfusGovernmentSecuritiesCashManagementAdministrativeShares Risk/Return Detail Data- Administrative Shares Prospectus - Dreyfus Government Securities Cash Management (- Administrative Shares) 7 false true R20.htm 020018 - Document - Risk/Return Summary {Unlabeled} - Administrative Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Administrative Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledAdministrativeSharesProspectusDreyfusTreasuryAgencyCashManagementAdministrativeShares Risk/Return Summary- Administrative Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Administrative Shares) 8 false false R25.htm 020023 - Disclosure - Risk/Return Detail Data {Elements} - Administrative Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Administrative Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsAdministrativeSharesProspectusDreyfusTreasuryAgencyCashManagementAdministrativeShares Risk/Return Detail Data- Administrative Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Administrative Shares) 9 false true R26.htm 020024 - Document - Risk/Return Summary {Unlabeled} - Administrative Shares Prospectus - Dreyfus Treasury Securities Cash Management (Administrative Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledAdministrativeSharesProspectusDreyfusTreasurySecuritiesCashManagementAdministrativeShares Risk/Return Summary- Administrative Shares Prospectus - Dreyfus Treasury Securities Cash Management (Administrative Shares) 10 false false R31.htm 020029 - Disclosure - Risk/Return Detail Data {Elements} - Administrative Shares Prospectus - Dreyfus Treasury Securities Cash Management (Administrative Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsAdministrativeSharesProspectusDreyfusTreasurySecuritiesCashManagementAdministrativeShares Risk/Return Detail Data- Administrative Shares Prospectus - Dreyfus Treasury Securities Cash Management (Administrative Shares) 11 false true R32.htm 020030 - Document - Risk/Return Summary {Unlabeled} - Administrative Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Administrative Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledAdministrativeSharesProspectusDreyfusTaxExemptCashManagementFundDREYFUSTAXEXEMPTCASHMANAGEMENTAdministrativeShares Risk/Return Summary- Administrative Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Administrative Shares) 12 false false R37.htm 020035 - Disclosure - Risk/Return Detail Data {Elements} - Administrative Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Administrative Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsAdministrativeSharesProspectusDreyfusTaxExemptCashManagementFundDREYFUSTAXEXEMPTCASHMANAGEMENTAdministrativeShares Risk/Return Detail Data- Administrative Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Administrative Shares) 13 false true R38.htm 020036 - Document - Risk/Return Summary {Unlabeled} - Administrative Shares Prospectus - Dreyfus Municipal Cash Management Plus (Administrative Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledAdministrativeSharesProspectusDreyfusMunicipalCashManagementPlusAdministrativeShares Risk/Return Summary- Administrative Shares Prospectus - Dreyfus Municipal Cash Management Plus (Administrative Shares) 14 false false R43.htm 020041 - Disclosure - Risk/Return Detail Data {Elements} - Administrative Shares Prospectus - Dreyfus Municipal Cash Management Plus (Administrative Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsAdministrativeSharesProspectusDreyfusMunicipalCashManagementPlusAdministrativeShares Risk/Return Detail Data- Administrative Shares Prospectus - Dreyfus Municipal Cash Management Plus (Administrative Shares) 15 false true R44.htm 020042 - Document - Risk/Return Summary {Unlabeled} - Administrative Shares Prospectus - Dreyfus New York Municipal Cash Management (Administrative Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledAdministrativeSharesProspectusDreyfusNewYorkMunicipalCashManagementAdministrativeShares Risk/Return Summary- Administrative Shares Prospectus - Dreyfus New York Municipal Cash Management (Administrative Shares) 16 false false R49.htm 020047 - Disclosure - Risk/Return Detail Data {Elements} - Administrative Shares Prospectus - Dreyfus New York Municipal Cash Management (Administrative Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsAdministrativeSharesProspectusDreyfusNewYorkMunicipalCashManagementAdministrativeShares Risk/Return Detail Data- Administrative Shares Prospectus - Dreyfus New York Municipal Cash Management (Administrative Shares) 17 false true R50.htm 020048 - Document - Risk/Return Summary {Unlabeled} - Agency Shares Prospectus - Dreyfus Cash Management (Agency Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledAgencySharesProspectusDreyfusCashManagementAgencyShares Risk/Return Summary- Agency Shares Prospectus - Dreyfus Cash Management (Agency Shares) 18 false false R55.htm 020053 - Disclosure - Risk/Return Detail Data {Elements} - Agency Shares Prospectus - Dreyfus Cash Management (Agency Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsAgencySharesProspectusDreyfusCashManagementAgencyShares Risk/Return Detail Data- Agency Shares Prospectus - Dreyfus Cash Management (Agency Shares) 19 false true R56.htm 020054 - Document - Risk/Return Summary {Unlabeled} - Agency Shares Prospectus - Dreyfus Government Cash Management (Agency Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledAgencySharesProspectusDreyfusGovernmentCashManagementAgencyShares Risk/Return Summary- Agency Shares Prospectus - Dreyfus Government Cash Management (Agency Shares) 20 false false R61.htm 020059 - Disclosure - Risk/Return Detail Data {Elements} - Agency Shares Prospectus - Dreyfus Government Cash Management (Agency Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsAgencySharesProspectusDreyfusGovernmentCashManagementAgencyShares Risk/Return Detail Data- Agency Shares Prospectus - Dreyfus Government Cash Management (Agency Shares) 21 false true R62.htm 020060 - Document - Risk/Return Summary {Unlabeled} - Agency Shares Prospectus - Dreyfus Government Securities Cash Management (- Agency Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledAgencySharesProspectusDreyfusGovernmentSecuritiesCashManagementAgencyShares Risk/Return Summary- Agency Shares Prospectus - Dreyfus Government Securities Cash Management (- Agency Shares) 22 false false R67.htm 020065 - Disclosure - Risk/Return Detail Data {Elements} - Agency Shares Prospectus - Dreyfus Government Securities Cash Management (- Agency Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsAgencySharesProspectusDreyfusGovernmentSecuritiesCashManagementAgencyShares Risk/Return Detail Data- Agency Shares Prospectus - Dreyfus Government Securities Cash Management (- Agency Shares) 23 false true R68.htm 020066 - Document - Risk/Return Summary {Unlabeled} - Agency Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Agency Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledAgencySharesProspectusDreyfusTreasuryAgencyCashManagementAgencyShares Risk/Return Summary- Agency Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Agency Shares) 24 false false R73.htm 020071 - Disclosure - Risk/Return Detail Data {Elements} - Agency Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Agency Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsAgencySharesProspectusDreyfusTreasuryAgencyCashManagementAgencyShares Risk/Return Detail Data- Agency Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Agency Shares) 25 false true R74.htm 020072 - Document - Risk/Return Summary {Unlabeled} - Agency Shares Prospectus - Dreyfus Treasury Securities Cash Management (Agency Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledAgencySharesProspectusDreyfusTreasurySecuritiesCashManagementAgencyShares Risk/Return Summary- Agency Shares Prospectus - Dreyfus Treasury Securities Cash Management (Agency Shares) 26 false false R79.htm 020077 - Disclosure - Risk/Return Detail Data {Elements} - Agency Shares Prospectus - Dreyfus Treasury Securities Cash Management (Agency Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsAgencySharesProspectusDreyfusTreasurySecuritiesCashManagementAgencyShares Risk/Return Detail Data- Agency Shares Prospectus - Dreyfus Treasury Securities Cash Management (Agency Shares) 27 false true R80.htm 020078 - Document - Risk/Return Summary {Unlabeled} - Institutional Shares Prospectus - Dreyfus Cash Management (Institutional Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInstitutionalSharesProspectusDreyfusCashManagementInstitutionalShares Risk/Return Summary- Institutional Shares Prospectus - Dreyfus Cash Management (Institutional Shares) 28 false false R85.htm 020083 - Disclosure - Risk/Return Detail Data {Elements} - Institutional Shares Prospectus - Dreyfus Cash Management (Institutional Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInstitutionalSharesProspectusDreyfusCashManagementInstitutionalShares Risk/Return Detail Data- Institutional Shares Prospectus - Dreyfus Cash Management (Institutional Shares) 29 false true R86.htm 020084 - Document - Risk/Return Summary {Unlabeled} - Institutional Shares Prospectus - Dreyfus Government Cash Management (dreyfus government cash mangement - Institutional Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInstitutionalSharesProspectusDreyfusGovernmentCashManagementdreyfusgovernmentcashmangementInstitutionalShares Risk/Return Summary- Institutional Shares Prospectus - Dreyfus Government Cash Management (dreyfus government cash mangement - Institutional Shares) 30 false false R91.htm 020089 - Disclosure - Risk/Return Detail Data {Elements} - Institutional Shares Prospectus - Dreyfus Government Cash Management (dreyfus government cash mangement - Institutional Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInstitutionalSharesProspectusDreyfusGovernmentCashManagementdreyfusgovernmentcashmangementInstitutionalShares Risk/Return Detail Data- Institutional Shares Prospectus - Dreyfus Government Cash Management (dreyfus government cash mangement - Institutional Shares) 31 false true R92.htm 020090 - Document - Risk/Return Summary {Unlabeled} - Institutional Shares Prospectus - Dreyfus Government Securities Cash Management (- Institutional Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInstitutionalSharesProspectusDreyfusGovernmentSecuritiesCashManagementInstitutionalShares Risk/Return Summary- Institutional Shares Prospectus - Dreyfus Government Securities Cash Management (- Institutional Shares) 32 false false R97.htm 020095 - Disclosure - Risk/Return Detail Data {Elements} - Institutional Shares Prospectus - Dreyfus Government Securities Cash Management (- Institutional Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInstitutionalSharesProspectusDreyfusGovernmentSecuritiesCashManagementInstitutionalShares Risk/Return Detail Data- Institutional Shares Prospectus - Dreyfus Government Securities Cash Management (- Institutional Shares) 33 false true R98.htm 020096 - Document - Risk/Return Summary {Unlabeled} - Institutional Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Institutional Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInstitutionalSharesProspectusDreyfusTreasuryAgencyCashManagementInstitutionalShares Risk/Return Summary- Institutional Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Institutional Shares) 34 false false R103.htm 020101 - Disclosure - Risk/Return Detail Data {Elements} - Institutional Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Institutional Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInstitutionalSharesProspectusDreyfusTreasuryAgencyCashManagementInstitutionalShares Risk/Return Detail Data- Institutional Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Institutional Shares) 35 false true R104.htm 020102 - Document - Risk/Return Summary {Unlabeled} - Institutional Shares Prospectus - Dreyfus Treasury Securities Cash Management (Institutional Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInstitutionalSharesProspectusDreyfusTreasurySecuritiesCashManagementInstitutionalShares Risk/Return Summary- Institutional Shares Prospectus - Dreyfus Treasury Securities Cash Management (Institutional Shares) 36 false false R109.htm 020107 - Disclosure - Risk/Return Detail Data {Elements} - Institutional Shares Prospectus - Dreyfus Treasury Securities Cash Management (Institutional Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInstitutionalSharesProspectusDreyfusTreasurySecuritiesCashManagementInstitutionalShares Risk/Return Detail Data- Institutional Shares Prospectus - Dreyfus Treasury Securities Cash Management (Institutional Shares) 37 false true R110.htm 020108 - Document - Risk/Return Summary {Unlabeled} - Institutional Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Institutional Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInstitutionalSharesProspectusDreyfusTaxExemptCashManagementFundDREYFUSTAXEXEMPTCASHMANAGEMENTInstitutionalShares Risk/Return Summary- Institutional Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Institutional Shares) 38 false false R115.htm 020113 - Disclosure - Risk/Return Detail Data {Elements} - Institutional Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Institutional Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInstitutionalSharesProspectusDreyfusTaxExemptCashManagementFundDREYFUSTAXEXEMPTCASHMANAGEMENTInstitutionalShares Risk/Return Detail Data- Institutional Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Institutional Shares) 39 false true R116.htm 020114 - Document - Risk/Return Summary {Unlabeled} - Institutional Shares Prospectus - Dreyfus Municipal Cash Management Plus (Institutional Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInstitutionalSharesProspectusDreyfusMunicipalCashManagementPlusInstitutionalShares Risk/Return Summary- Institutional Shares Prospectus - Dreyfus Municipal Cash Management Plus (Institutional Shares) 40 false false R121.htm 020119 - Disclosure - Risk/Return Detail Data {Elements} - Institutional Shares Prospectus - Dreyfus Municipal Cash Management Plus (Institutional Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInstitutionalSharesProspectusDreyfusMunicipalCashManagementPlusInstitutionalShares Risk/Return Detail Data- Institutional Shares Prospectus - Dreyfus Municipal Cash Management Plus (Institutional Shares) 41 false true R122.htm 020120 - Document - Risk/Return Summary {Unlabeled} - Institutional Shares Prospectus - Dreyfus New York Municipal Cash Management (Institutional Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInstitutionalSharesProspectusDreyfusNewYorkMunicipalCashManagementInstitutionalShares Risk/Return Summary- Institutional Shares Prospectus - Dreyfus New York Municipal Cash Management (Institutional Shares) 42 false false R127.htm 020125 - Disclosure - Risk/Return Detail Data {Elements} - Institutional Shares Prospectus - Dreyfus New York Municipal Cash Management (Institutional Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInstitutionalSharesProspectusDreyfusNewYorkMunicipalCashManagementInstitutionalShares Risk/Return Detail Data- Institutional Shares Prospectus - Dreyfus New York Municipal Cash Management (Institutional Shares) 43 false true R128.htm 020126 - Document - Risk/Return Summary {Unlabeled} - Institutional Shares Prospectus - Dreyfus California AMT-Free Municipal Cash Management (Institutional Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInstitutionalSharesProspectusDreyfusCaliforniaAMTFreeMunicipalCashManagementInstitutionalShares Risk/Return Summary- Institutional Shares Prospectus - Dreyfus California AMT-Free Municipal Cash Management (Institutional Shares) 44 false false R133.htm 020131 - Disclosure - Risk/Return Detail Data {Elements} - Institutional Shares Prospectus - Dreyfus California AMT-Free Municipal Cash Management (Institutional Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInstitutionalSharesProspectusDreyfusCaliforniaAMTFreeMunicipalCashManagementInstitutionalShares Risk/Return Detail Data- Institutional Shares Prospectus - Dreyfus California AMT-Free Municipal Cash Management (Institutional Shares) 45 false true R134.htm 020132 - Document - Risk/Return Summary {Unlabeled} - Investor Shares Prospectus - Dreyfus Cash Management (Investor Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInvestorSharesProspectusDreyfusCashManagementInvestorShares Risk/Return Summary- Investor Shares Prospectus - Dreyfus Cash Management (Investor Shares) 46 false false R139.htm 020137 - Disclosure - Risk/Return Detail Data {Elements} - Investor Shares Prospectus - Dreyfus Cash Management (Investor Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInvestorSharesProspectusDreyfusCashManagementInvestorShares Risk/Return Detail Data- Investor Shares Prospectus - Dreyfus Cash Management (Investor Shares) 47 false true R140.htm 020138 - Document - Risk/Return Summary {Unlabeled} - Investor Shares Prospectus - Dreyfus Government Cash Management (dreyfus government cash management - Investor Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInvestorSharesProspectusDreyfusGovernmentCashManagementdreyfusgovernmentcashmanagementInvestorShares Risk/Return Summary- Investor Shares Prospectus - Dreyfus Government Cash Management (dreyfus government cash management - Investor Shares) 48 false false R145.htm 020143 - Disclosure - Risk/Return Detail Data {Elements} - Investor Shares Prospectus - Dreyfus Government Cash Management (dreyfus government cash management - Investor Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInvestorSharesProspectusDreyfusGovernmentCashManagementdreyfusgovernmentcashmanagementInvestorShares Risk/Return Detail Data- Investor Shares Prospectus - Dreyfus Government Cash Management (dreyfus government cash management - Investor Shares) 49 false true R146.htm 020144 - Document - Risk/Return Summary {Unlabeled} - Investor Shares Prospectus - Dreyfus Government Securities Cash Management (- Investor Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInvestorSharesProspectusDreyfusGovernmentSecuritiesCashManagementInvestorShares Risk/Return Summary- Investor Shares Prospectus - Dreyfus Government Securities Cash Management (- Investor Shares) 50 false false R151.htm 020149 - Disclosure - Risk/Return Detail Data {Elements} - Investor Shares Prospectus - Dreyfus Government Securities Cash Management (- Investor Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInvestorSharesProspectusDreyfusGovernmentSecuritiesCashManagementInvestorShares Risk/Return Detail Data- Investor Shares Prospectus - Dreyfus Government Securities Cash Management (- Investor Shares) 51 false true R152.htm 020150 - Document - Risk/Return Summary {Unlabeled} - Investor Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Investor Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInvestorSharesProspectusDreyfusTreasuryAgencyCashManagementInvestorShares Risk/Return Summary- Investor Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Investor Shares) 52 false false R157.htm 020155 - Disclosure - Risk/Return Detail Data {Elements} - Investor Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Investor Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInvestorSharesProspectusDreyfusTreasuryAgencyCashManagementInvestorShares Risk/Return Detail Data- Investor Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Investor Shares) 53 false true R158.htm 020156 - Document - Risk/Return Summary {Unlabeled} - Investor Shares Prospectus - Dreyfus Treasury Securities Cash Management (Investor Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInvestorSharesProspectusDreyfusTreasurySecuritiesCashManagementInvestorShares Risk/Return Summary- Investor Shares Prospectus - Dreyfus Treasury Securities Cash Management (Investor Shares) 54 false false R163.htm 020161 - Disclosure - Risk/Return Detail Data {Elements} - Investor Shares Prospectus - Dreyfus Treasury Securities Cash Management (Investor Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInvestorSharesProspectusDreyfusTreasurySecuritiesCashManagementInvestorShares Risk/Return Detail Data- Investor Shares Prospectus - Dreyfus Treasury Securities Cash Management (Investor Shares) 55 false true R164.htm 020162 - Document - Risk/Return Summary {Unlabeled} - Investor Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Investor Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInvestorSharesProspectusDreyfusTaxExemptCashManagementFundDREYFUSTAXEXEMPTCASHMANAGEMENTInvestorShares Risk/Return Summary- Investor Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Investor Shares) 56 false false R169.htm 020167 - Disclosure - Risk/Return Detail Data {Elements} - Investor Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Investor Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInvestorSharesProspectusDreyfusTaxExemptCashManagementFundDREYFUSTAXEXEMPTCASHMANAGEMENTInvestorShares Risk/Return Detail Data- Investor Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Investor Shares) 57 false true R170.htm 020168 - Document - Risk/Return Summary {Unlabeled} - Investor Shares Prospectus - Dreyfus Municipal Cash Management Plus (Investor Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInvestorSharesProspectusDreyfusMunicipalCashManagementPlusInvestorShares Risk/Return Summary- Investor Shares Prospectus - Dreyfus Municipal Cash Management Plus (Investor Shares) 58 false false R175.htm 020173 - Disclosure - Risk/Return Detail Data {Elements} - Investor Shares Prospectus - Dreyfus Municipal Cash Management Plus (Investor Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInvestorSharesProspectusDreyfusMunicipalCashManagementPlusInvestorShares Risk/Return Detail Data- Investor Shares Prospectus - Dreyfus Municipal Cash Management Plus (Investor Shares) 59 false true R176.htm 020174 - Document - Risk/Return Summary {Unlabeled} - Investor Shares Prospectus - Dreyfus New York Municipal Cash Management (Investor Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInvestorSharesProspectusDreyfusNewYorkMunicipalCashManagementInvestorShares Risk/Return Summary- Investor Shares Prospectus - Dreyfus New York Municipal Cash Management (Investor Shares) 60 false false R181.htm 020179 - Disclosure - Risk/Return Detail Data {Elements} - Investor Shares Prospectus - Dreyfus New York Municipal Cash Management (Investor Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInvestorSharesProspectusDreyfusNewYorkMunicipalCashManagementInvestorShares Risk/Return Detail Data- Investor Shares Prospectus - Dreyfus New York Municipal Cash Management (Investor Shares) 61 false true R182.htm 020180 - Document - Risk/Return Summary {Unlabeled} - Investor Shares Prospectus - Dreyfus California AMT-Free Municipal Cash Management (Investor Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledInvestorSharesProspectusDreyfusCaliforniaAMTFreeMunicipalCashManagementInvestorShares Risk/Return Summary- Investor Shares Prospectus - Dreyfus California AMT-Free Municipal Cash Management (Investor Shares) 62 false false R187.htm 020185 - Disclosure - Risk/Return Detail Data {Elements} - Investor Shares Prospectus - Dreyfus California AMT-Free Municipal Cash Management (Investor Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsInvestorSharesProspectusDreyfusCaliforniaAMTFreeMunicipalCashManagementInvestorShares Risk/Return Detail Data- Investor Shares Prospectus - Dreyfus California AMT-Free Municipal Cash Management (Investor Shares) 63 false true R188.htm 020186 - Document - Risk/Return Summary {Unlabeled} - Participant Shares Prospectus - Dreyfus Cash Management (participant shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledParticipantSharesProspectusDreyfusCashManagementparticipantshares Risk/Return Summary- Participant Shares Prospectus - Dreyfus Cash Management (participant shares) 64 false false R193.htm 020191 - Disclosure - Risk/Return Detail Data {Elements} - Participant Shares Prospectus - Dreyfus Cash Management (participant shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsParticipantSharesProspectusDreyfusCashManagementparticipantshares Risk/Return Detail Data- Participant Shares Prospectus - Dreyfus Cash Management (participant shares) 65 false true R194.htm 020192 - Document - Risk/Return Summary {Unlabeled} - Participant Shares Prospectus - Dreyfus Government Cash Management (- Participant Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledParticipantSharesProspectusDreyfusGovernmentCashManagementParticipantShares Risk/Return Summary- Participant Shares Prospectus - Dreyfus Government Cash Management (- Participant Shares) 66 false false R199.htm 020197 - Disclosure - Risk/Return Detail Data {Elements} - Participant Shares Prospectus - Dreyfus Government Cash Management (- Participant Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsParticipantSharesProspectusDreyfusGovernmentCashManagementParticipantShares Risk/Return Detail Data- Participant Shares Prospectus - Dreyfus Government Cash Management (- Participant Shares) 67 false true R200.htm 020198 - Document - Risk/Return Summary {Unlabeled} - Participant Shares Prospectus - Dreyfus Government Securities Cash Management (- Participant Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledParticipantSharesProspectusDreyfusGovernmentSecuritiesCashManagementParticipantShares Risk/Return Summary- Participant Shares Prospectus - Dreyfus Government Securities Cash Management (- Participant Shares) 68 false false R205.htm 020203 - Disclosure - Risk/Return Detail Data {Elements} - Participant Shares Prospectus - Dreyfus Government Securities Cash Management (- Participant Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsParticipantSharesProspectusDreyfusGovernmentSecuritiesCashManagementParticipantShares Risk/Return Detail Data- Participant Shares Prospectus - Dreyfus Government Securities Cash Management (- Participant Shares) 69 false true R206.htm 020204 - Document - Risk/Return Summary {Unlabeled} - Participant Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Participant Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledParticipantSharesProspectusDreyfusTreasuryAgencyCashManagementParticipantShares Risk/Return Summary- Participant Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Participant Shares) 70 false false R211.htm 020209 - Disclosure - Risk/Return Detail Data {Elements} - Participant Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Participant Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsParticipantSharesProspectusDreyfusTreasuryAgencyCashManagementParticipantShares Risk/Return Detail Data- Participant Shares Prospectus - Dreyfus Treasury & Agency Cash Management (Participant Shares) 71 false true R212.htm 020210 - Document - Risk/Return Summary {Unlabeled} - Participant Shares Prospectus - Dreyfus Treasury Securities Cash Management (Participant Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledParticipantSharesProspectusDreyfusTreasurySecuritiesCashManagementParticipantShares Risk/Return Summary- Participant Shares Prospectus - Dreyfus Treasury Securities Cash Management (Participant Shares) 72 false false R217.htm 020215 - Disclosure - Risk/Return Detail Data {Elements} - Participant Shares Prospectus - Dreyfus Treasury Securities Cash Management (Participant Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsParticipantSharesProspectusDreyfusTreasurySecuritiesCashManagementParticipantShares Risk/Return Detail Data- Participant Shares Prospectus - Dreyfus Treasury Securities Cash Management (Participant Shares) 73 false true R218.htm 020216 - Document - Risk/Return Summary {Unlabeled} - Participant Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Participant Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledParticipantSharesProspectusDreyfusTaxExemptCashManagementFundDREYFUSTAXEXEMPTCASHMANAGEMENTParticipantShares Risk/Return Summary- Participant Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Participant Shares) 74 false false R223.htm 020221 - Disclosure - Risk/Return Detail Data {Elements} - Participant Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Participant Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsParticipantSharesProspectusDreyfusTaxExemptCashManagementFundDREYFUSTAXEXEMPTCASHMANAGEMENTParticipantShares Risk/Return Detail Data- Participant Shares Prospectus - Dreyfus Tax Exempt Cash Management Fund (DREYFUS TAX EXEMPT CASH MANAGEMENT - Participant Shares) 75 false true R224.htm 020222 - Document - Risk/Return Summary {Unlabeled} - Participant Shares Prospectus - Dreyfus Municipal Cash Management Plus (Participant Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledParticipantSharesProspectusDreyfusMunicipalCashManagementPlusParticipantShares Risk/Return Summary- Participant Shares Prospectus - Dreyfus Municipal Cash Management Plus (Participant Shares) 76 false false R229.htm 020227 - Disclosure - Risk/Return Detail Data {Elements} - Participant Shares Prospectus - Dreyfus Municipal Cash Management Plus (Participant Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsParticipantSharesProspectusDreyfusMunicipalCashManagementPlusParticipantShares Risk/Return Detail Data- Participant Shares Prospectus - Dreyfus Municipal Cash Management Plus (Participant Shares) 77 false true R230.htm 020228 - Document - Risk/Return Summary {Unlabeled} - Participant Shares Prospectus - Dreyfus New York Municipal Cash Management (Participant Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledParticipantSharesProspectusDreyfusNewYorkMunicipalCashManagementParticipantShares Risk/Return Summary- Participant Shares Prospectus - Dreyfus New York Municipal Cash Management (Participant Shares) 78 false false R235.htm 020233 - Disclosure - Risk/Return Detail Data {Elements} - Participant Shares Prospectus - Dreyfus New York Municipal Cash Management (Participant Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsParticipantSharesProspectusDreyfusNewYorkMunicipalCashManagementParticipantShares Risk/Return Detail Data- Participant Shares Prospectus - Dreyfus New York Municipal Cash Management (Participant Shares) 79 false true R236.htm 020234 - Document - Risk/Return Summary {Unlabeled} - Participant Shares Prospectus - Dreyfus California AMT-Free Municipal Cash Management (Participant Shares) Sheet http://dreyfus.com/20160527/role/DocumentRiskReturnSummaryUnlabeledParticipantSharesProspectusDreyfusCaliforniaAMTFreeMunicipalCashManagementParticipantShares Risk/Return Summary- Participant Shares Prospectus - Dreyfus California AMT-Free Municipal Cash Management (Participant Shares) 80 false false R241.htm 020239 - Disclosure - Risk/Return Detail Data {Elements} - Participant Shares Prospectus - Dreyfus California AMT-Free Municipal Cash Management (Participant Shares) Sheet http://dreyfus.com/20160527/role/DisclosureRiskReturnDetailDataElementsParticipantSharesProspectusDreyfusCaliforniaAMTFreeMunicipalCashManagementParticipantShares Risk/Return Detail Data- Participant Shares Prospectus - Dreyfus California AMT-Free Municipal Cash Management (Participant Shares) 81 false false R242.htm 040000 - Disclosure - Risk/Return Detail Data {Elements} Sheet http://xbrl.sec.gov/rr/role/RiskReturnDetailData Risk/Return Detail Data 82 false false All Reports Book All Reports ck0000796251-20160527.xml ck0000796251-20160527.xsd ck0000796251-20160527_cal.xml ck0000796251-20160527_def.xml ck0000796251-20160527_lab.xml ck0000796251-20160527_pre.xml BarChart1.png BarChart2.png BarChart3.png BarChart4.png BarChart5.png BarChart6.png BarChart7.png BarChart8.png BarChart9.png BarChart10.png BarChart11.png BarChart12.png BarChart13.png BarChart14.png BarChart15.png BarChart16.png BarChart17.png BarChart18.png BarChart19.png BarChart20.png BarChart21.png BarChart22.png BarChart23.png BarChart24.png BarChart25.png BarChart26.png BarChart27.png BarChart28.png BarChart29.png BarChart30.png BarChart31.png BarChart32.png BarChart33.png BarChart34.png BarChart35.png BarChart36.png BarChart37.png BarChart38.png BarChart39.png BarChart40.png true true