Vanguard Short-Term Bond Index Fund Average Annual Total Returns - Admiral Prospectus [Member] |
12 Months Ended | 60 Months Ended | 83 Months Ended | 120 Months Ended |
|---|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| Bloomberg U.S. 1-5 Year Gov/Credit Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)[Member] | ||||
| Prospectus [Line Items] | ||||
| Average Annual Return, Percent | 6.11% | 1.56% | 2.17% | |
| 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%) | 1.90% | 2.05% |
| Admiral Shares | ||||
| Prospectus [Line Items] | ||||
| Average Annual Return, Percent | 6.08% | 1.52% | 2.11% | |
| Admiral Shares | After Taxes on Distributions | ||||
| Prospectus [Line Items] | ||||
| Average Annual Return, Percent | 4.43% | 0.50% | 1.20% | |
| Admiral Shares | After Taxes on Distributions and Sales | ||||
| Prospectus [Line Items] | ||||
| Average Annual Return, Percent | 3.58% | 0.72% | 1.22% |