U S Treasury Securities [Member] Thirty One To 90 Days [Member] Ninety One To 180 Days [Member] One To 7 Days [Member] One Hundred Eighty One Days Or More [Member] Eight To 30 Days [Member] C000242775 [Member] Select Shares C000259499 [Member] Cash Reserve Shares C000026172 [Member] Institutional Shares C000242772 [Member] Premier Shares C000242773 [Member] Administrative Shares C000026171 [Member] Service Shares C000242774 [Member] Advisor Shares Investment Type [Axis] Net Assets Investment Company Portfolio Turnover No Trading Symbol Flag