v3.26.1
Vanguard Long-Term Corporate Bond Index Fund Expense Example - Institutional Prospectus [Member] - Vanguard Long-Term Corporate Bond Index Fund - Institutional Shares
Aug. 31, 2025
USD ($)
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 103
Expense Example, with Redemption, 3 Years 110
Expense Example, with Redemption, 5 Years 117
Expense Example, with Redemption, 10 Years $ 138