S000001245 [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 |
|
| SMALL CAP INDEX FUND | SMALL CAP INDEX FUND | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 12.87% | 11.48% | 16.83% | (20.51%) | 14.67% | 19.54% | 25.22% | (11.14%) | 14.59% | 21.17% |