Short-Term Bond Portfolio Average Annual Total Returns |
12 Months Ended | 60 Months Ended | 120 Months Ended |
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| Bloomberg® 1-3 Year U.S. Government/Credit Bond Index(reflects no deduction for fees, expenses or taxes)[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 5.35% | 1.97% | 2.09% |
| Bloomberg® U.S. Aggregate Bond Index(reflects no deduction for fees, expenses or taxes)[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 7.30% | (0.36%) | 2.01% |
| Short-Term Bond Portfolio | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 5.70% | 2.20% | 2.40% |