v3.26.1
First Trust S and P REIT Index Fund Expense Example, No Redemption - First Trust S and P REIT Index Fund - First Trust S and P REIT Index Fund
Dec. 31, 2025
USD ($)
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year $ 51
Expense Example, No Redemption, 3 Years 163
Expense Example, No Redemption, 5 Years 284
Expense Example, No Redemption, 10 Years $ 640