First Trust Bloomberg Nuclear Power ETF Performance Management - First Trust Bloomberg Nuclear Power ETF	Sep. 30, 2025
Prospectus [Line Items]
Bar Chart and Performance Table [Heading]	<span style="font-family:Arial;font-size:9.90pt;font-weight:bold;">Performance</span>
Performance Narrative [Text Block]	The Fund does not have performance information available for a full calendar year.
Performance One Year or Less [Text]	<span style="font-family:Arial;font-size:9.00pt;">The Fund does not have performance information available for a full calendar year.</span>