v3.26.1
First Trust Natural Gas ETF Expense Example, No Redemption - First Trust Natural Gas ETF - First Trust Natural Gas ETF
Dec. 31, 2025
USD ($)
Prospectus [Line Items]  
Expense Example, No Redemption, 1 Year $ 60
Expense Example, No Redemption, 3 Years 189
Expense Example, No Redemption, 5 Years 329
Expense Example, No Redemption, 10 Years $ 738