S000010615 [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 |
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| S000010615 [Member] | C000029350 [Member] | ||||||||||||
| Prospectus [Line Items] | ||||||||||||
| Annual Return [Percent] | [1] | 3.00% | 7.46% | 6.85% | (17.33%) | 6.34% | 3.54% | 8.44% | 2.20% | 6.82% | 0.48% | |
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