v3.26.1
Vanguard GNMA Fund Expense Example - Retail Prospectus [Member] - Vanguard GNMA Fund
Jan. 31, 2026
USD ($)
Investor Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 22
Expense Example, with Redemption, 3 Years 68
Expense Example, with Redemption, 5 Years 118
Expense Example, with Redemption, 10 Years 268
Admiral Shares  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 11
Expense Example, with Redemption, 3 Years 35
Expense Example, with Redemption, 5 Years 62
Expense Example, with Redemption, 10 Years $ 141