2.2.0.25 true Sheet 0011 - Document - Document And Entity Information {Elements} Document And Entity Information http://www.seic.com/role/DocumentDocumentandEntityInformation false R1.xml false Sheet 0112 - Document - Risk/Return Summary {Unlabeled} (SIMT Multi-Strategy Alternative Fund) Risk/Return Summary (SIMT Multi-Strategy Alternative Fund) http://www.seic.com/role/RiskReturn_S000028026Member true R2.xml false Sheet 040000 - Disclosure - Risk/Return Detail Data {Elements} Risk/Return Detail Data http://xbrl.sec.gov/rr/role/RiskReturnDetailData false R5.xml false Book All Reports All Reports false 1 3 3 0 2 26 true false eol_0001104659-11-024169_STD_1_20110131_0 8 eol_0001104659-11-024169_STD_1_20110131_0_396770x-9995647_396840x-9993227 11 eol_0001104659-11-024169_STD_1_20110131_0_396770x-9995647_429423x-9995651 7 true true