S000003888 [Member] Average Annual Total Returns |
12 Months Ended | 60 Months Ended | 120 Months Ended |
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| Russell 3000 Index (no deduction for fees, expenses or taxes) | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 17.15% | 13.15% | 14.29% |
| Russell 2000 Value Index (no deduction for fees, expenses or taxes) | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 12.59% | 8.88% | 9.27% |
| Class IA Shares | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 5.46% | 11.28% | 9.39% |
| Class IB Shares | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 5.27% | 10.99% | 9.13% |