v3.26.1
Annual Total Returns - Institutional Class
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Boston Partners All-Cap Value Fund                    
Prospectus [Line Items]                    
Annual Return [Percent] 17.52% 9.99% 12.41% (2.42%) 25.59% 4.12% 27.88% (11.87%) 17.87% 14.82%
Boston Partners Global Equity Fund                    
Prospectus [Line Items]                    
Annual Return [Percent] 34.02% 7.21% 14.11% (3.07%) 21.76% 3.26% 18.77% (13.15%) 20.37% 8.50%
Boston Partners Long/Short Equity Fund                    
Prospectus [Line Items]                    
Annual Return [Percent] 28.32% 13.28% 15.20% 7.20% 32.03% (6.35%) 9.12% (15.47%) 2.77% 22.48%
Boston Partners Long/Short Research Fund                    
Prospectus [Line Items]                    
Annual Return [Percent] 14.96% 13.48% 4.74% 6.48% 23.80% (8.25%) 12.58% (10.59%) 10.10% 3.62%
Boston Partners Small Cap Value Fund II                    
Prospectus [Line Items]                    
Annual Return [Percent] 7.50% 14.02% 16.68% (11.49%) 25.78% 1.60% 28.02% (16.34%) 9.78% 25.97%
WPG Partners Select Small Cap Value Fund                    
Prospectus [Line Items]                    
Annual Return [Percent] 6.63% 7.95% 19.73% 3.46%            
WPG Partners Small Cap Value Diversified Fund                    
Prospectus [Line Items]                    
Annual Return [Percent] 10.57% 14.30% 2.04% 40.06% (1.31%) 23.35% (21.77%) 5.68% 19.63% (13.74%)