Vanguard Total Bond Market Index Fund Expense Example - Institutional Prospectus [Member] - Vanguard Total Bond Market Index Fund |
Dec. 31, 2025
USD ($)
|
|---|---|
| Institutional Shares | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | $ 3 |
| Expense Example, with Redemption, 3 Years | 8 |
| Expense Example, with Redemption, 5 Years | 14 |
| Expense Example, with Redemption, 10 Years | 32 |
| Institutional Plus Shares | |
| Prospectus [Line Items] | |
| Expense Example, with Redemption, 1 Year | 2 |
| Expense Example, with Redemption, 3 Years | 6 |
| Expense Example, with Redemption, 5 Years | 11 |
| Expense Example, with Redemption, 10 Years | $ 26 |