Short-Term Investment-Grade Portfolio Average Annual Total Returns - Portfolio [Member] |
12 Months Ended | 60 Months Ended | 120 Months Ended |
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| Bloomberg U.S. 1-5 Year Credit Bond Index (reflects no deduction for fees, expenses, or taxes)[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 6.74% | 2.15% | 2.84% |
| 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 Investment-Grade Portfolio | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 6.85% | 2.23% | 2.81% |