Vanguard Extended Market Index Fund Investment Objectives and Goals - Admiral Prospectus [Member] - Vanguard Extended Market Index Fund |
Dec. 31, 2025 |
|---|---|
| Prospectus [Line Items] | |
| Risk/Return [Heading] | <span style="color:#000000;font-family:Arial;font-size:13pt;font-weight:bold;">Vanguard Extended Market Index Fund</span> |
| Objective [Heading] | <span style="color:#000000;font-family:Arial;font-size:10pt;font-weight:bold;">Investment Objective</span> |
| Objective, Primary [Text Block] | Vanguard Extended Market Index Fund (the “Fund”) seeks to track the performance of a benchmark index that measures the investment return of small- and mid-capitalization stocks. |