| Label | Element | Value |
|---|---|---|
| Class X | U.S. Treasury Repurchase Agreements [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 43.20% |
| Class X | U.S. Treasury Debt [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 27.80% |
| Class X | U.S. Government Agency Debt [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 22.40% |
| Class X | U.S. Government Agency Repurchase Agreements [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 5.80% |
| Class X | Investment Companies [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | 0.90% |
| Class X | Other Assets and Liabilities, Net [Member] | ||
| Holdings [Line Items] | oef_HoldingsLineItems | |
| Percent of Net Asset Value | oef_PctOfNav | (0.10%) |