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 |
|||
| S000010777 [Member] | C000029788 [Member] | ||||||||||||
| Prospectus [Line Items] | ||||||||||||
| Annual Return [Percent] | [1] | 5.66% | 5.94% | 7.04% | (4.93%) | 0.48% | 3.26% | 4.82% | 0.47% | 0.79% | 1.46% | |
| ||||||||||||