v3.26.1
Class I [Member] Annual Total Returns
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Class I | UBS Ultra Short Income Fund | Class I              
Prospectus [Line Items]              
Annual Return [Percent] 4.65% 5.43% 5.74% (0.18%) (0.02%) 0.73% 3.02%