S000010780 [Member] Annual Total Returns |
12 Months Ended | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
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 |
Dec. 31, 2015 |
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| S000010780 [Member] | C000029800 [Member] | ||||||||||||
| Prospectus [Line Items] | ||||||||||||
| Annual Return [Percent] | [1] | 0.96% | 4.56% | (6.59%) | 0.76% | 3.32% | 6.24% | 0.92% | 4.47% | (0.33%) | 2.45% | |
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