3.20.1 html 43 87 1 false 46 0 false 0 false false R1.htm 000001 - Document - Document and Entity Information Sheet http://www.bny.com/20200319/role/DocumentAndEntityInformation Document and Entity Information 1 false false R2.htm 020000 - Document - Risk/Return Summary {Unlabeled} - BNY Mellon Dynamic Value Fund Sheet http://www.bny.com/20200319/role/DocumentRiskReturnSummaryUnlabeledBNYMellonDynamicValueFund Risk/Return Summary- BNY Mellon Dynamic Value Fund 2 false false R3.htm 020001 - Disclosure - Risk/Return Detail Data {Elements} - BNY Mellon Dynamic Value Fund Sheet http://www.bny.com/20200319/role/DisclosureRiskReturnDetailDataElementsBNYMellonDynamicValueFund Risk/Return Detail Data- BNY Mellon Dynamic Value Fund 3 false false R4.htm 020002 - Document - Risk/Return Summary {Unlabeled} - BNY Mellon Opportunistic Midcap Value Fund Sheet http://www.bny.com/20200319/role/DocumentRiskReturnSummaryUnlabeledBNYMellonOpportunisticMidcapValueFund Risk/Return Summary- BNY Mellon Opportunistic Midcap Value Fund 4 false false R5.htm 020003 - Disclosure - Risk/Return Detail Data {Elements} - BNY Mellon Opportunistic Midcap Value Fund Sheet http://www.bny.com/20200319/role/DisclosureRiskReturnDetailDataElementsBNYMellonOpportunisticMidcapValueFund Risk/Return Detail Data- BNY Mellon Opportunistic Midcap Value Fund 5 false false R6.htm 020004 - Document - Risk/Return Summary {Unlabeled} - BNY Mellon Opportunistic Small Cap Fund Sheet http://www.bny.com/20200319/role/DocumentRiskReturnSummaryUnlabeledBNYMellonOpportunisticSmallCapFund Risk/Return Summary- BNY Mellon Opportunistic Small Cap Fund 6 false false R7.htm 020005 - Disclosure - Risk/Return Detail Data {Elements} - BNY Mellon Opportunistic Small Cap Fund Sheet http://www.bny.com/20200319/role/DisclosureRiskReturnDetailDataElementsBNYMellonOpportunisticSmallCapFund Risk/Return Detail Data- BNY Mellon Opportunistic Small Cap Fund 7 false false R8.htm 020006 - Document - Risk/Return Summary {Unlabeled} - BNY Mellon Structured Midcap Fund Sheet http://www.bny.com/20200319/role/DocumentRiskReturnSummaryUnlabeledBNYMellonStructuredMidcapFund Risk/Return Summary- BNY Mellon Structured Midcap Fund 8 false false R9.htm 020007 - Disclosure - Risk/Return Detail Data {Elements} - BNY Mellon Structured Midcap Fund Sheet http://www.bny.com/20200319/role/DisclosureRiskReturnDetailDataElementsBNYMellonStructuredMidcapFund Risk/Return Detail Data- BNY Mellon Structured Midcap Fund 9 false false R10.htm 020008 - Document - Risk/Return Summary {Unlabeled} - BNY Mellon Technology Growth Fund Sheet http://www.bny.com/20200319/role/DocumentRiskReturnSummaryUnlabeledBNYMellonTechnologyGrowthFund Risk/Return Summary- BNY Mellon Technology Growth Fund 10 false false R11.htm 020009 - Disclosure - Risk/Return Detail Data {Elements} - BNY Mellon Technology Growth Fund Sheet http://www.bny.com/20200319/role/DisclosureRiskReturnDetailDataElementsBNYMellonTechnologyGrowthFund Risk/Return Detail Data- BNY Mellon Technology Growth Fund 11 false false R12.htm 020010 - Document - Risk/Return Summary {Unlabeled} - BNY Mellon Floating Rate Income Fund Sheet http://www.bny.com/20200319/role/DocumentRiskReturnSummaryUnlabeledBNYMellonFloatingRateIncomeFund Risk/Return Summary- BNY Mellon Floating Rate Income Fund 12 false false R13.htm 020011 - Disclosure - Risk/Return Detail Data {Elements} - BNY Mellon Floating Rate Income Fund Sheet http://www.bny.com/20200319/role/DisclosureRiskReturnDetailDataElementsBNYMellonFloatingRateIncomeFund Risk/Return Detail Data- BNY Mellon Floating Rate Income Fund 13 false false R14.htm 020012 - Document - Risk/Return Summary {Unlabeled} - BNY Mellon AMT-Free Municipal Bond Fund Sheet http://www.bny.com/20200319/role/DocumentRiskReturnSummaryUnlabeledBNYMellonAMTFreeMunicipalBondFund Risk/Return Summary- BNY Mellon AMT-Free Municipal Bond Fund 14 false false R15.htm 020013 - Disclosure - Risk/Return Detail Data {Elements} - BNY Mellon AMT-Free Municipal Bond Fund Sheet http://www.bny.com/20200319/role/DisclosureRiskReturnDetailDataElementsBNYMellonAMTFreeMunicipalBondFund Risk/Return Detail Data- BNY Mellon AMT-Free Municipal Bond Fund 15 false false R16.htm 020014 - Document - Risk/Return Summary {Unlabeled} - BNY Mellon High Yield Municipal Bond Fund Sheet http://www.bny.com/20200319/role/DocumentRiskReturnSummaryUnlabeledBNYMellonHighYieldMunicipalBondFund Risk/Return Summary- BNY Mellon High Yield Municipal Bond Fund 16 false false R17.htm 020015 - Disclosure - Risk/Return Detail Data {Elements} - BNY Mellon High Yield Municipal Bond Fund Sheet http://www.bny.com/20200319/role/DisclosureRiskReturnDetailDataElementsBNYMellonHighYieldMunicipalBondFund Risk/Return Detail Data- BNY Mellon High Yield Municipal Bond Fund 17 false false R18.htm 020016 - Document - Risk/Return Summary {Unlabeled} - BNY Mellon Municipal Bond Fund Sheet http://www.bny.com/20200319/role/DocumentRiskReturnSummaryUnlabeledBNYMellonMunicipalBondFund Risk/Return Summary- BNY Mellon Municipal Bond Fund 18 false false R19.htm 020017 - Disclosure - Risk/Return Detail Data {Elements} - BNY Mellon Municipal Bond Fund Sheet http://www.bny.com/20200319/role/DisclosureRiskReturnDetailDataElementsBNYMellonMunicipalBondFund Risk/Return Detail Data- BNY Mellon Municipal Bond Fund 19 false false R20.htm 040000 - Disclosure - Risk/Return Detail Data {Elements} Sheet http://xbrl.sec.gov/rr/role/RiskReturnDetailData Risk/Return Detail Data 20 false false All Reports Book All Reports ck0000075176-20200319.xml ck0000075176-20200319.xsd ck0000075176-20200319_cal.xml ck0000075176-20200319_def.xml ck0000075176-20200319_lab.xml ck0000075176-20200319_pre.xml http://xbrl.sec.gov/dei/2018-01-31 http://xbrl.sec.gov/rr/2018-01-31 true true