Vanguard Total Bond Market Index Fund Average Annual Total Returns - ETF Prospectus [Member] |
12 Months Ended | 60 Months Ended | 120 Months Ended |
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| Bloomberg U.S. Aggregate Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 7.21% | (0.37%) | 2.05% |
| ETF Shares | After Taxes on Distributions | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 5.43% | (1.62%) | 0.83% |
| ETF Shares | After Taxes on Distributions and Sales | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 4.18% | (0.83%) | 1.03% |
| ETF Shares | Based on NAV[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 7.11% | (0.40%) | 2.00% |
| ETF Shares | Based on Market Price[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 7.08% | (0.44%) | 1.98% |