Vanguard Municipal Low Duration Fund Annual Fund Operating Expenses - Investor Prospectus [Member] - Vanguard Municipal Low Duration Fund - Investor Shares	Aug. 31, 2025
Prospectus [Line Items]
Management Fees (as a percentage of Assets)	0.01%
Distribution and Service (12b-1) Fees	0.00%
Other Expenses (as a percentage of Assets):	0.00%
Expenses (as a percentage of Assets)	0.01%

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