v3.25.4
First Trust Senior Loan Fund Expense Example, No Redemption - First Trust Senior Loan Fund - First Trust Senior Loan Fund
Oct. 31, 2025
USD ($)
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year $ 72
Expense Example, No Redemption, 3 Years 224
Expense Example, No Redemption, 5 Years 390
Expense Example, No Redemption, 10 Years $ 871