v3.26.3
Shareholder Report, Line Graph (Details) 190904_Boston Partners Long-Short Research Fund_Investor Class_TSR Annual {Investor Class} - USD ($)
12 Months Ended
Aug. 31, 2025
Aug. 31, 2024
Aug. 31, 2023
Aug. 31, 2022
Aug. 31, 2021
Aug. 31, 2020
Aug. 31, 2019
Aug. 31, 2018
Aug. 31, 2017
Aug. 31, 2016
Aug. 31, 2026
Investor Class                      
Account Value [Line Items]                      
Line Graph and Table Measure Name                     Investor Class
Accumulated Value $ 17,284 $ 15,919 $ 13,442 $ 12,572 $ 11,767 $ 9,335 $ 10,409 $ 10,873 $ 10,660 $ 10,000 $ 19,551
S&P 500 Total Return Index [Member]                      
Account Value [Line Items]                      
Line Graph and Table Measure Name                     S&P 500 Total Return Index
Accumulated Value $ 34,718 $ 29,960 $ 23,566 $ 20,325 $ 22,895 $ 17,455 $ 14,315 $ 13,909 $ 11,623 $ 10,000 $ 41,793