2.2.0.25 true Sheet 007001 - Document - Risk/Return Summary {Unlabeled} (Small Cap Core Equity Portfolio) (INV INST) Risk/Return Summary (Small Cap Core Equity Portfolio) (INV INST) http://www.blackrock.com/role/DocumentRiskReturnSummaryUnlabeledSmallCapCoreEquityPortfolioInvInst true R1.xml false Sheet 007008 - Document - Risk/Return Summary {Unlabeled} (Small Cap Core Equity Portfolio) (Service Shares) Risk/Return Summary (Small Cap Core Equity Portfolio) (Service Shares) http://www.blackrock.com/role/DocumentRiskReturnSummaryUnlabeledSmallCapCoreEquityPortfolioServiceShares true R8.xml false Sheet 040000 - Disclosure - Risk/Return Detail Data {Elements} Risk/Return Detail Data http://xbrl.sec.gov/rr/role/RiskReturnDetailData false R14.xml false Book All Reports All Reports false 1 14 11 0 2 89 true false Duration_1_28_2011_To_1_28_201192 3 Duration_1_28_2011_To_1_28_20118 39 Duration_1_28_2011_To_1_28_201110 4 Duration_1_28_2011_To_1_28_2011 8 Duration_1_28_2011_To_1_28_20114 22 Duration_1_28_2011_To_1_28_201111 4 Duration_1_28_2011_To_1_28_20115 22 Duration_1_28_2011_To_1_28_20119 4 Duration_1_28_2011_To_1_28_20117 44 Duration_1_28_2011_To_1_28_201113 3 Duration_1_28_2011_To_1_28_20116 33 Duration_1_28_2011_To_1_28_20112 18 Duration_1_28_2011_To_1_28_201112 4 Duration_1_28_2011_To_1_28_20113 33 true true