Vanguard 500 Index Fund Average Annual Total Returns - Investor Prospectus [Member] |
12 Months Ended | 60 Months Ended | 120 Months Ended |
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| Standard & Poor's 500 Index (reflects no deduction for fees, expenses, or taxes)[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 17.88% | 14.42% | 14.82% |
| Dow Jones U.S. Total Stock Market Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 17.05% | 13.07% | 14.21% |
| Investor Shares | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 17.71% | 14.26% | 14.66% |
| Investor Shares | After Taxes on Distributions | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 17.40% | 13.90% | 14.23% |
| Investor Shares | After Taxes on Distributions and Sales | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 10.67% | 11.38% | 12.24% |