Institutional Shares [Member] Performance Management - Institutional Shares [Member] - UBS Select 100% US Treasury Institutional Fund |
Apr. 30, 2026 |
|---|---|
| Prospectus [Line Items] | |
| Bar Chart and Performance Table [Heading] | Performance Risk/return bar chart and table |
| Performance Narrative [Text Block] | The following bar chart and table provide information about the fund’s performance and thus give some indication of the risks of an investment in the fund. The bar chart shows how the fund’s performance has varied over its first calendar year of operations. The table that follows the bar chart shows the average annual returns over various time periods for the fund’s shares. The fund’s past performance does not necessarily indicate how the fund will perform in the future.
|
| Performance Past Does Not Indicate Future [Text] | The fund’s past performance does not necessarily indicate how the fund will perform in the future. |
| Performance Information Illustrates Variability of Returns [Text] | The following bar chart and table provide information about the fund’s performance and thus give some indication of the risks of an investment in the fund. |
| Bar Chart [Heading] | UBS Select 100% US Treasury Institutional Fund Annual Total Returns Total Return of Institutional Shares (2025 was the fund’s first full calendar year of operations) |
| Bar Chart Closing [Text Block] | Total return January 1 to June 30, 2026: 1.75% Best quarter during year shown—3Q 2025: 1.03% Worst quarter during year shown—4Q 2025: 0.94% Updated performance information is available (1) by contacting your Financial Advisor, (2) by calling 1‑888‑793 8637 (Option #1) and (3) on the fund’s website at https://www.ubs.com/usmoneymarketfunds.
|
| Performance Table Heading | Average annual total returns (for the period ended December 31, 2025) |
| Performance Availability Website Address [Text] | https://www.ubs.com/usmoneymarketfunds |
| Performance Availability Phone [Text] | 1‑888‑793 8637 |
| Institutional Shares For Participants | |
| Prospectus [Line Items] | |
| Year to Date Return, Label [Optional Text] | Total return |
| Bar Chart, Year to Date Return | 1.75% |
| Bar Chart, Year to Date Return, Date | Jun. 30, 2026 |
| Highest Quarterly Return, Label [Optional Text] | Best quarter |
| Highest Quarterly Return | 1.03% |
| Highest Quarterly Return, Date | Sep. 30, 2025 |
| Lowest Quarterly Return, Label [Optional Text] | Worst quarter |
| Lowest Quarterly Return | 0.94% |
| Lowest Quarterly Return, Date | Dec. 31, 2025 |