3.10.0.1 html 41 92 1 true 32 0 false 2 false false R1.htm 000001 - Document - Document and Entity Information Sheet http://Dreyfus.com/20181228/role/DocumentAndEntityInformation Document and Entity Information 1 false true R2.htm 020000 - Document - Risk/Return Summary {Unlabeled} - Dreyfus Opportunistic Midcap Value Fund Sheet http://Dreyfus.com/20181228/role/DocumentRiskReturnSummaryUnlabeledDreyfusOpportunisticMidcapValueFund Risk/Return Summary- Dreyfus Opportunistic Midcap Value Fund 2 false false R9.htm 020007 - Disclosure - Risk/Return Detail Data {Elements} - Dreyfus Opportunistic Midcap Value Fund Sheet http://Dreyfus.com/20181228/role/DisclosureRiskReturnDetailDataElementsDreyfusOpportunisticMidcapValueFund Risk/Return Detail Data- Dreyfus Opportunistic Midcap Value Fund 3 false true R10.htm 020008 - Document - Risk/Return Summary {Unlabeled} - Dreyfus Opportunistic Small Cap Fund Sheet http://Dreyfus.com/20181228/role/DocumentRiskReturnSummaryUnlabeledDreyfusOpportunisticSmallCapFund Risk/Return Summary- Dreyfus Opportunistic Small Cap Fund 4 false false R16.htm 020014 - Disclosure - Risk/Return Detail Data {Elements} - Dreyfus Opportunistic Small Cap Fund Sheet http://Dreyfus.com/20181228/role/DisclosureRiskReturnDetailDataElementsDreyfusOpportunisticSmallCapFund Risk/Return Detail Data- Dreyfus Opportunistic Small Cap Fund 5 false true R17.htm 020015 - Document - Risk/Return Summary {Unlabeled} - Dreyfus Strategic Value Fund Sheet http://Dreyfus.com/20181228/role/DocumentRiskReturnSummaryUnlabeledDreyfusStrategicValueFund Risk/Return Summary- Dreyfus Strategic Value Fund 6 false false R24.htm 020022 - Disclosure - Risk/Return Detail Data {Elements} - Dreyfus Strategic Value Fund Sheet http://Dreyfus.com/20181228/role/DisclosureRiskReturnDetailDataElementsDreyfusStrategicValueFund Risk/Return Detail Data- Dreyfus Strategic Value Fund 7 false true R25.htm 020023 - Document - Risk/Return Summary {Unlabeled} - Dreyfus Structured Midcap Fund Sheet http://Dreyfus.com/20181228/role/DocumentRiskReturnSummaryUnlabeledDreyfusStructuredMidcapFund Risk/Return Summary- Dreyfus Structured Midcap Fund 8 false false R32.htm 020030 - Disclosure - Risk/Return Detail Data {Elements} - Dreyfus Structured Midcap Fund Sheet http://Dreyfus.com/20181228/role/DisclosureRiskReturnDetailDataElementsDreyfusStructuredMidcapFund Risk/Return Detail Data- Dreyfus Structured Midcap Fund 9 false true R33.htm 020031 - Document - Risk/Return Summary {Unlabeled} - Dreyfus Technology Growth Fund Sheet http://Dreyfus.com/20181228/role/DocumentRiskReturnSummaryUnlabeledDreyfusTechnologyGrowthFund Risk/Return Summary- Dreyfus Technology Growth Fund 10 false false R40.htm 020038 - Disclosure - Risk/Return Detail Data {Elements} - Dreyfus Technology Growth Fund Sheet http://Dreyfus.com/20181228/role/DisclosureRiskReturnDetailDataElementsDreyfusTechnologyGrowthFund Risk/Return Detail Data- Dreyfus Technology Growth Fund 11 false false R41.htm 040000 - Disclosure - Risk/Return Detail Data {Elements} Sheet http://xbrl.sec.gov/rr/role/RiskReturnDetailData Risk/Return Detail Data 12 false false All Reports Book All Reports ck0000914775-20181228.xml ck0000914775-20181228.xsd ck0000914775-20181228_cal.xml ck0000914775-20181228_def.xml ck0000914775-20181228_lab.xml ck0000914775-20181228_pre.xml BarChart1.png BarChart2.png BarChart3.png BarChart4.png BarChart5.png http://xbrl.sec.gov/rr/2012-01-31 http://xbrl.sec.gov/dei/2012-01-31 true true