Vanguard Intermediate-Term Treasury Index Fund 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 |
|
| Institutional Prospectus [Member] | Vanguard Intermediate-Term Treasury Index Fund | Institutional Shares | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 1.27% | 4.43% | (10.65%) | (2.59%) | 7.65% | 6.31% | 1.32% | 1.60% | 1.15% | 1.68% |