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Vanguard Intermediate-Term Investment-Grade Fund Average Annual Total Returns - Retail Prospectus [Member]
12 Months Ended 60 Months Ended 120 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Bloomberg U.S. 5-10 Year Credit Bond Index (reflects no deduction for fees, expenses, or taxes)[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent 9.57% 0.77% 3.55%
Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees, expenses, or taxes)[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent 7.30% (0.36%) 2.01%
Investor Shares      
Prospectus [Line Items]      
Average Annual Return, Percent 9.53% 0.85% 3.16%
Investor Shares | After Taxes on Distributions      
Prospectus [Line Items]      
Average Annual Return, Percent 7.37% (0.74%) 1.59%
Investor Shares | After Taxes on Distributions and Sales      
Prospectus [Line Items]      
Average Annual Return, Percent 5.59% (0.03%) 1.77%
Admiral Shares      
Prospectus [Line Items]      
Average Annual Return, Percent 9.64% 0.95% 3.27%