Vanguard Cash Reserves Federal Money Market Fund Expense Example - Retail Prospectus [Member] - Vanguard Cash Reserves Federal Money Market Fund - Admiral Shares	Aug. 31, 2025 USD ($)
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 10
Expense Example, with Redemption, 3 Years	32
Expense Example, with Redemption, 5 Years	56
Expense Example, with Redemption, 10 Years	$ 128

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
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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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