XML 14 R3.htm IDEA: XBRL DOCUMENT v2.4.0.6
Annual Fund Operating Expenses (Vanguard Federal Money Market Fund - Investor Shares, Vanguard Federal Money Market Fund)
12 Months Ended
Aug. 31, 2011
Vanguard Federal Money Market Fund - Investor Shares | Vanguard Federal Money Market Fund
 
Annual Fund Operating Expenses (Expenses that you pay each year as a percentage of the value of your investment)  
Management Expenses 0.16%
12b-1 Distribution Fee none
Other Expenses 0.04%
Total Annual Fund Operating Expenses 0.20% [1]
[1] Vanguard and the Fund's Board have voluntarily agreed to temporarily limit certain net operating expenses in excess of the Fund's daily yield so as to maintain a zero or positive yield for the Fund. Vanguard and the Fund's Board may terminate the temporary expense limitation at any time.