S000003882 [Member] Average Annual Total Returns |
12 Months Ended | 60 Months Ended | 120 Months Ended |
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| Class IA Shares | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 3.95% | 2.96% | 1.87% |
| Class IB Shares | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 3.69% | 2.77% | 1.70% |