v3.26.1
Investment Objectives and Goals - Natixis Funds Trust I
Dec. 31, 2025
Mirova Global Megatrends Fund  
Prospectus [Line Items]  
Risk/Return [Heading] Mirova Global Megatrends Fund
Objective [Heading] Investment Goal
Objective, Primary [Text Block]
The Fund seeks long-term capital appreciation.
Vaughan Nelson Small Cap Fund  
Prospectus [Line Items]  
Risk/Return [Heading] Vaughan Nelson Small Cap Fund
Objective [Heading] Investment Goal
Objective, Primary [Text Block]
The Fund seeks capital appreciation.
Natixis Oakmark International Fund  
Prospectus [Line Items]  
Risk/Return [Heading] Natixis Oakmark International Fund
Objective [Heading] Investment Goal
Objective, Primary [Text Block]
The Fund seeks long-term capital appreciation.
Natixis U.S. Equity Opportunities Fund  
Prospectus [Line Items]  
Risk/Return [Heading] Natixis U.S. Equity Opportunities Fund
Objective [Heading] Investment Goal
Objective, Primary [Text Block]
The Fund seeks long-term growth of capital.