Vanguard Extended Duration Treasury Index Fund Expense Example - Institutional Prospectus [Member] - Vanguard Extended Duration Treasury Index Fund |
Aug. 31, 2025
USD ($)
|
|---|---|
| Institutional Shares | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | $ 55 |
| Expense Example, with Redemption, 3 Years | 66 |
| Expense Example, with Redemption, 5 Years | 78 |
| Expense Example, with Redemption, 10 Years | 114 |
| Institutional Plus Shares | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 53 |
| Expense Example, with Redemption, 3 Years | 60 |
| Expense Example, with Redemption, 5 Years | 67 |
| Expense Example, with Redemption, 10 Years | $ 88 |