S000003864 [Member] Expense Example - BlackRock Advantage Large Cap Core Portfolio - BlackRock Advantage Large Cap Core Portfolio	Dec. 31, 2025 USD ($)
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 49
Expense Example, with Redemption, 3 Years	174
Expense Example, with Redemption, 5 Years	309
Expense Example, with Redemption, 10 Years	$ 705

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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