v3.25.3
First Trust Small Cap Value AlphaDEX Fund Expense Example, No Redemption - First Trust Small Cap Value AlphaDEX Fund - First Trust Small Cap Value AlphaDEX Fund
Jul. 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