Vanguard Long-Term Bond Index Fund 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 |
|
| Institutional Prospectus [Member] | Vanguard Long-Term Bond Index Fund | Institutional Shares | ||||||||
| Prospectus [Line Items] | ||||||||
| Annual Return [Percent] | 6.58% | (4.13%) | 7.54% | (27.20%) | (2.64%) | 16.25% | 19.12% | (4.41%) |