v3.25.3
First Trust Consumer Discretionary AlphaDEX Fund Expense Example, No Redemption - First Trust Consumer Discretionary AlphaDEX Fund - First Trust Consumer Discretionary AlphaDEX Fund
Jul. 31, 2025
USD ($)
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year $ 61
Expense Example, No Redemption, 3 Years 192
Expense Example, No Redemption, 5 Years 335
Expense Example, No Redemption, 10 Years $ 750