Vanguard Institutional Total Stock Market 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 Institutional Total Stock Market Index Fund | Institutional Shares | ||||||||
| Prospectus [Line Items] | ||||||||
| Annual Return [Percent] | 17.15% | 23.77% | 26.05% | (19.49%) | 25.75% | 20.99% | 30.86% | (5.15%) |