v3.25.3
First Trust Mid Cap Value AlphaDEX Fund Expense Example, No Redemption - First Trust Mid Cap Value AlphaDEX Fund - First Trust Mid Cap Value AlphaDEX Fund
Jul. 31, 2025
USD ($)
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year $ 76
Expense Example, No Redemption, 3 Years 237
Expense Example, No Redemption, 5 Years 411
Expense Example, No Redemption, 10 Years $ 918