Vanguard Mid-Cap 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 |
|
| Admiral Prospectus [Member] | Vanguard Mid-Cap Index Fund | Admiral Shares | ||||||||
| Prospectus [Line Items] | ||||||||
| Annual Return [Percent] | 11.67% | 15.22% | 15.98% | (18.71%) | 24.51% | 18.24% | 31.03% | (9.23%) |