Shares [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 |
|
| Shares [Member] | U.S. GOVERNMENT PORTFOLIO | Shares | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 4.12% | 5.09% | 4.92% | 1.28% | 0.02% | 0.36% | 2.04% | 1.64% | 0.68% | 0.13% |