3.19.2 html 5 96 1 false 6 0 false 1 false false R1.htm 000001 - Document - Document and Entity Information Sheet http://sei.com/20190710/role/DocumentAndEntityInformation Document and Entity Information 1 false true R2.htm 020000 - Document - Risk/Return Summary {Unlabeled} - Class F Prospectus - SIMT Conservative Income Fund Sheet http://sei.com/20190710/role/DocumentRiskReturnSummaryUnlabeledClassFProspectusSIMTConservativeIncomeFund Risk/Return Summary- Class F Prospectus - SIMT Conservative Income Fund 2 false false R4.htm 020002 - Disclosure - Risk/Return Detail Data {Elements} - Class F Prospectus - SIMT Conservative Income Fund Sheet http://sei.com/20190710/role/DisclosureRiskReturnDetailDataElementsClassFProspectusSIMTConservativeIncomeFund Risk/Return Detail Data- Class F Prospectus - SIMT Conservative Income Fund 3 false true R5.htm 020003 - Document - Risk/Return Summary {Unlabeled} - Class I Prospectus - Simt Large Cap Value Fund Sheet http://sei.com/20190710/role/DocumentRiskReturnSummaryUnlabeledClassIProspectusSimtLargeCapValueFund Risk/Return Summary- Class I Prospectus - Simt Large Cap Value Fund 4 false false R7.htm 020005 - Disclosure - Risk/Return Detail Data {Elements} - Class I Prospectus - Simt Large Cap Value Fund Sheet http://sei.com/20190710/role/DisclosureRiskReturnDetailDataElementsClassIProspectusSimtLargeCapValueFund Risk/Return Detail Data- Class I Prospectus - Simt Large Cap Value Fund 5 false false R8.htm 040000 - Disclosure - Risk/Return Detail Data {Elements} Sheet http://xbrl.sec.gov/rr/role/RiskReturnDetailData Risk/Return Detail Data 6 false false All Reports Book All Reports ck0000804239-20190710.xml ck0000804239-20190710.xsd ck0000804239-20190710_cal.xml ck0000804239-20190710_def.xml ck0000804239-20190710_lab.xml ck0000804239-20190710_pre.xml BarChart1.png BarChart2.png http://xbrl.sec.gov/dei/2018-01-31 http://xbrl.sec.gov/rr/2018-01-31 true true