S000003864 [Member] Average Annual Total Returns |
12 Months Ended | 60 Months Ended | 120 Months Ended |
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| Russell 1000® Index (Reflects no deduction for fees, expenses or taxes) | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 17.37% | 13.59% | 14.59% |
| BlackRock Advantage Large Cap Core Portfolio | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 20.20% | 14.27% | 14.50% |