State Street Institutional Treasury Money Market Fund Average Annual Total Returns |
12 Months Ended | 60 Months Ended | 120 Months Ended |
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| Premier Class | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 4.22% | 3.16% | 2.09% |