v3.26.1
Annual Total Returns - Natixis Funds Trust I
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
Mirova Global Megatrends Fund | Class Y                    
Prospectus [Line Items]                    
Annual Return [Percent] 15.32% 13.06% 18.63% (22.33%) 18.06% 32.42% 32.99% (6.32%) 30.75%  
Vaughan Nelson Small Cap Fund | Class Y                    
Prospectus [Line Items]                    
Annual Return [Percent] 12.16% 5.05% 25.10% (9.98%) 30.61% 9.23% 24.88% (14.61%) 6.60% 20.53%
Natixis Oakmark International Fund | Class A                    
Prospectus [Line Items]                    
Annual Return [Percent] 25.00% (5.13%) 18.94% (15.91%) 8.73% 4.06% 24.35% (24.15%) 29.56% 8.19%
Natixis U.S. Equity Opportunities Fund | Class Y                    
Prospectus [Line Items]                    
Annual Return [Percent] 17.62% 25.54% 37.35% (20.95%) 23.48% 22.36% 31.36% (6.24%) 26.60% 12.13%