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Vanguard Intermediate-Term Corporate Bond Index Fund Average Annual Total Returns - Institutional Prospectus [Member]
12 Months Ended 60 Months Ended 120 Months Ended
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2024
Bloomberg U.S. 5-10 Year Corporate Bond Index (reflects no deduction for fees, expenses, or taxes)[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent 3.21% 0.89% 2.82%
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%
Institutional Shares      
Prospectus [Line Items]      
Average Annual Return, Percent 3.04% 0.80% 2.71%
Institutional Shares | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 1.21% (0.55%) 1.30%
Institutional Shares | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 1.78% 0.06% 1.47%