First Trust Bloomberg Nuclear Power ETF Investment Objectives and Goals - First Trust Bloomberg Nuclear Power ETF	Sep. 30, 2025
Prospectus [Line Items]
Risk/Return [Heading]	<span style="color:#000000;font-family:Arial;font-size:12.60pt;font-weight:bold;">First Trust Bloomberg Nuclear Power ETF (RCTR)</span>
Objective [Heading]	<span style="color:#000000;font-family:Arial;font-size:9.90pt;font-weight:bold;">Investment Objective</span>
Objective, Primary [Text Block]	The First Trust Bloomberg Nuclear Power ETF (the “Fund”) seeks investment results that correspond generally to the price and yield (before the Fund’s fees and expenses) of an index called the Bloomberg Nuclear Power Index (the “Index”).