FT Vest U.S. Equity Dual Directional Buffer ETF - May S000095241 [Member] C000263945 [Member] Absence Of An Active Market Risk [Member] Buffered Loss Risk [Member] Cap Change Risk [Member] Capped Upside Risk [Member] Cash Transactions Risk [Member] Counterparty Risk [Member] Current Market Conditions Risk [Member] Cyber Security Risk [Member] Flex Options Risk [Member] Flex Options Valuation Risk [Member] Index Or Model Constituent Risk [Member] Information Technology Companies Risk [Member] Inverse Performance Risk [Member] Large Capitalization Companies Risk [Member] Management Risk [Member] Market Risk [Member] New Fund Risk [Member] Risk Nondiversified [Member] Operational Risk [Member] Options Risk [Member] Premium Discount Risk [Member] Special Tax Risk [Member] Target Outcome Period Risk [Member] Trading Issues Risk [Member] Underlying ETF Concentration Risk [Member] Underlying ETF Equity Risk [Member] Underlying ETF Risk [Member]