Long-Term US Government Bond Portfolio Annual Total Returns |
12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Long-Term US Government Bond Portfolio | Long-Term US Government Bond Portfolio | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 6.15% | (5.78%) | 3.33% | (29.53%) | (5.37%) | 17.37% | 13.17% | (2.04%) | 8.28% | 1.09% |