v3.26.1
Expense Example, No Redemption - LOOMIS SAYLES FUNDS II - Class C
Dec. 31, 2025
USD ($)
Loomis Sayles High Income Fund  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year $ 173
Expense Example, No Redemption, 3 Years 615
Expense Example, No Redemption, 5 Years 1,084
Expense Example, No Redemption, 10 Years 2,188
Loomis Sayles International Growth Fund  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 198
Expense Example, No Redemption, 3 Years 753
Expense Example, No Redemption, 5 Years 1,334
Expense Example, No Redemption, 10 Years 2,738
Loomis Sayles Investment Grade Bond Fund  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 151
Expense Example, No Redemption, 3 Years 478
Expense Example, No Redemption, 5 Years 829
Expense Example, No Redemption, 10 Years 1,617
Loomis Sayles Strategic Income Fund  
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year 170
Expense Example, No Redemption, 3 Years 543
Expense Example, No Redemption, 5 Years 941
Expense Example, No Redemption, 10 Years $ 1,858