Load [Member] 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 |
|
| Intermediate Government Bond Series | Intermediate Government Bond Series | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 5.04% | 1.66% | 4.17% | (3.50%) | (1.11%) | 3.91% | 4.50% | 0.44% | 1.35% | 1.77% |