v3.25.2
Form N-CSR Cover
12 Months Ended
Jul. 31, 2025
Shareholder Report [Line Items]  
Document Type N-CSR
Amendment Flag false
Registrant Name FIRST TRUST EXCHANGE-TRADED ALPHADEX FUND
Entity Central Index Key 0001383496
Entity Investment Company Type N-1A
Document Period End Date Jul. 31, 2025