Vanguard Long-Term Corporate Bond Index Fund Average Annual Total Returns - Admiral Prospectus [Member] |
12 Months Ended | 60 Months Ended | 120 Months Ended |
|---|---|---|---|
Dec. 31, 2024 |
Dec. 31, 2024 |
Dec. 31, 2024 |
|
| Bloomberg U.S. 10+ Year Corporate Bond Index (reflects no deduction for fees, expenses, or taxes)[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | (1.95%) | (1.84%) | 2.20% |
| Bloomberg U.S. Aggregate Float Adjusted Index (reflects no deduction for fees, expenses, or taxes)[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 1.33% | (0.27%) | 1.39% |
| Admiral Shares | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | (2.90%) | (2.09%) | 2.04% |
| Admiral Shares | After Taxes on Distributions | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | (4.85%) | (3.70%) | 0.29% |
| Admiral Shares | After Taxes on Distributions and Sales | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | (1.70%) | (2.19%) | 0.82% |