v3.26.1
S000001266 [Member] Average Annual Total Returns
12 Months Ended 60 Months Ended 120 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
U.S. GOVERNMENT MONEY MARKET FUND      
Prospectus [Line Items]      
Average Annual Return, Percent 4.02% 2.99% 1.93%