Vanguard Municipal Low Duration Fund Expense Example - Investor Prospectus [Member] - Vanguard Municipal Low Duration Fund - Investor Shares	Aug. 31, 2025 USD ($)
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 1
Expense Example, with Redemption, 3 Years	3
Expense Example, with Redemption, 5 Years	6
Expense Example, with Redemption, 10 Years	$ 13

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 3
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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