110002 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - January Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 110003 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - January Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 110004 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - January Investment Strategy link:presentationLink link:definitionLink link:calculationLink 110005 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - January Investment Risks link:presentationLink link:definitionLink link:calculationLink 110006 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - January Performance Management link:presentationLink link:definitionLink link:calculationLink 120010 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - January Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 120020 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - January Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 120030 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - January Expense Example link:presentationLink link:definitionLink link:calculationLink 120040 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - January Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 120045 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - January Risks Data link:presentationLink link:definitionLink link:calculationLink 120050 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - January Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 120060 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - January Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 120070 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - January Market Index Performance link:presentationLink link:definitionLink link:calculationLink 110000 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - January N-1A Cover link:presentationLink link:definitionLink link:calculationLink 110001 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - January N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 210002 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - February Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 210003 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - February Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 210004 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - February Investment Strategy link:presentationLink link:definitionLink link:calculationLink 210005 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - February Investment Risks link:presentationLink link:definitionLink link:calculationLink 210006 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - February Performance Management link:presentationLink link:definitionLink link:calculationLink 220010 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - February Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 220020 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - February Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 220030 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - February Expense Example link:presentationLink link:definitionLink link:calculationLink 220040 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - February Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 220045 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - February Risks Data link:presentationLink link:definitionLink link:calculationLink 220050 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - February Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 220060 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - February Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 220070 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - February Market Index Performance link:presentationLink link:definitionLink link:calculationLink 210000 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - February N-1A Cover link:presentationLink link:definitionLink link:calculationLink 210001 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - February N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 310002 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - March Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 310003 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - March Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 310004 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - March Investment Strategy link:presentationLink link:definitionLink link:calculationLink 310005 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - March Investment Risks link:presentationLink link:definitionLink link:calculationLink 310006 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - March Performance Management link:presentationLink link:definitionLink link:calculationLink 320010 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - March Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 320020 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - March Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 320030 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - March Expense Example link:presentationLink link:definitionLink link:calculationLink 320040 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - March Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 320045 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - March Risks Data link:presentationLink link:definitionLink link:calculationLink 320050 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - March Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 320060 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - March Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 320070 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - March Market Index Performance link:presentationLink link:definitionLink link:calculationLink 310000 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - March N-1A Cover link:presentationLink link:definitionLink link:calculationLink 310001 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - March N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 410002 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - April Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 410003 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - April Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 410004 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - April Investment Strategy link:presentationLink link:definitionLink link:calculationLink 410005 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - April Investment Risks link:presentationLink link:definitionLink link:calculationLink 410006 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - April Performance Management link:presentationLink link:definitionLink link:calculationLink 420010 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - April Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 420020 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - April Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 420030 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - April Expense Example link:presentationLink link:definitionLink link:calculationLink 420040 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - April Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 420045 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - April Risks Data link:presentationLink link:definitionLink link:calculationLink 420050 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - April Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 420060 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - April Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 420070 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - April Market Index Performance link:presentationLink link:definitionLink link:calculationLink 410000 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - April N-1A Cover link:presentationLink link:definitionLink link:calculationLink 410001 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - April N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 510002 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - May Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 510003 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - May Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 510004 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - May Investment Strategy link:presentationLink link:definitionLink link:calculationLink 510005 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - May Investment Risks link:presentationLink link:definitionLink link:calculationLink 510006 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - May Performance Management link:presentationLink link:definitionLink link:calculationLink 520010 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - May Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 520020 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - May Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 520030 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - May Expense Example link:presentationLink link:definitionLink link:calculationLink 520040 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - May Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 520045 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - May Risks Data link:presentationLink link:definitionLink link:calculationLink 520050 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - May Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 520060 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - May Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 520070 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - May Market Index Performance link:presentationLink link:definitionLink link:calculationLink 510000 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - May N-1A Cover link:presentationLink link:definitionLink link:calculationLink 510001 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - May N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 610002 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - June Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 610003 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - June Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 610004 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - June Investment Strategy link:presentationLink link:definitionLink link:calculationLink 610005 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - June Investment Risks link:presentationLink link:definitionLink link:calculationLink 610006 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - June Performance Management link:presentationLink link:definitionLink link:calculationLink 620010 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - June Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 620020 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - June Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 620030 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - June Expense Example link:presentationLink link:definitionLink link:calculationLink 620040 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - June Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 620045 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - June Risks Data link:presentationLink link:definitionLink link:calculationLink 620050 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - June Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 620060 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - June Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 620070 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - June Market Index Performance link:presentationLink link:definitionLink link:calculationLink 610000 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - June N-1A Cover link:presentationLink link:definitionLink link:calculationLink 610001 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - June N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 710002 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - July Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 710003 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - July Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 710004 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - July Investment Strategy link:presentationLink link:definitionLink link:calculationLink 710005 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - July Investment Risks link:presentationLink link:definitionLink link:calculationLink 710006 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - July Performance Management link:presentationLink link:definitionLink link:calculationLink 720010 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - July Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 720020 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - July Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 720030 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - July Expense Example link:presentationLink link:definitionLink link:calculationLink 720040 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - July Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 720045 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - July Risks Data link:presentationLink link:definitionLink link:calculationLink 720050 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - July Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 720060 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - July Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 720070 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - July Market Index Performance link:presentationLink link:definitionLink link:calculationLink 710000 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - July N-1A Cover link:presentationLink link:definitionLink link:calculationLink 710001 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - July N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 810002 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - August Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 810003 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - August Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 810004 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - August Investment Strategy link:presentationLink link:definitionLink link:calculationLink 810005 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - August Investment Risks link:presentationLink link:definitionLink link:calculationLink 810006 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - August Performance Management link:presentationLink link:definitionLink link:calculationLink 820010 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - August Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 820020 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - August Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 820030 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - August Expense Example link:presentationLink link:definitionLink link:calculationLink 820040 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - August Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 820045 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - August Risks Data link:presentationLink link:definitionLink link:calculationLink 820050 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - August Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 820060 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - August Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 820070 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - August Market Index Performance link:presentationLink link:definitionLink link:calculationLink 810000 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - August N-1A Cover link:presentationLink link:definitionLink link:calculationLink 810001 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - August N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 910002 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - September Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 910003 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - September Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 910004 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - September Investment Strategy link:presentationLink link:definitionLink link:calculationLink 910005 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - September Investment Risks link:presentationLink link:definitionLink link:calculationLink 910006 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - September Performance Management link:presentationLink link:definitionLink link:calculationLink 920010 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - September Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 920020 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - September Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 920030 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - September Expense Example link:presentationLink link:definitionLink link:calculationLink 920040 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - September Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 920045 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - September Risks Data link:presentationLink link:definitionLink link:calculationLink 920050 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - September Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 920060 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - September Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 920070 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - September Market Index Performance link:presentationLink link:definitionLink link:calculationLink 910000 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - September N-1A Cover link:presentationLink link:definitionLink link:calculationLink 910001 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - September N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 1010002 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - October Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 1010003 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - October Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 1010004 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - October Investment Strategy link:presentationLink link:definitionLink link:calculationLink 1010005 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - October Investment Risks link:presentationLink link:definitionLink link:calculationLink 1010006 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - October Performance Management link:presentationLink link:definitionLink link:calculationLink 1020010 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - October Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 1020020 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - October Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 1020030 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - October Expense Example link:presentationLink link:definitionLink link:calculationLink 1020040 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - October Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 1020045 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - October Risks Data link:presentationLink link:definitionLink link:calculationLink 1020050 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - October Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1020060 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - October Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1020070 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - October Market Index Performance link:presentationLink link:definitionLink link:calculationLink 1010000 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - October N-1A Cover link:presentationLink link:definitionLink link:calculationLink 1010001 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - October N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 1110002 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - November Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 1110003 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - November Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 1110004 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - November Investment Strategy link:presentationLink link:definitionLink link:calculationLink 1110005 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - November Investment Risks link:presentationLink link:definitionLink link:calculationLink 1110006 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - November Performance Management link:presentationLink link:definitionLink link:calculationLink 1120010 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - November Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 1120020 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - November Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 1120030 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - November Expense Example link:presentationLink link:definitionLink link:calculationLink 1120040 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - November Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 1120045 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - November Risks Data link:presentationLink link:definitionLink link:calculationLink 1120050 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - November Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1120060 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - November Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1120070 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - November Market Index Performance link:presentationLink link:definitionLink link:calculationLink 1110000 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - November N-1A Cover link:presentationLink link:definitionLink link:calculationLink 1110001 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - November N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 1210002 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - December Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 1210003 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - December Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 1210004 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - December Investment Strategy link:presentationLink link:definitionLink link:calculationLink 1210005 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - December Investment Risks link:presentationLink link:definitionLink link:calculationLink 1210006 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - December Performance Management link:presentationLink link:definitionLink link:calculationLink 1220010 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - December Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 1220020 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - December Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 1220030 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - December Expense Example link:presentationLink link:definitionLink link:calculationLink 1220040 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - December Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 1220045 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - December Risks Data link:presentationLink link:definitionLink link:calculationLink 1220050 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - December Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1220060 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - December Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1220070 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - December Market Index Performance link:presentationLink link:definitionLink link:calculationLink 1210000 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - December N-1A Cover link:presentationLink link:definitionLink link:calculationLink 1210001 - Disclosure - FT Vest U.S. Equity Max Buffer ETF - December N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 1310002 - Disclosure - FT Vest Laddered U.S. Equity Equal Weight Buffer ETF Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 1310003 - Disclosure - FT Vest Laddered U.S. Equity Equal Weight Buffer ETF Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 1310004 - Disclosure - FT Vest Laddered U.S. Equity Equal Weight Buffer ETF Investment Strategy link:presentationLink link:definitionLink link:calculationLink 1310005 - Disclosure - FT Vest Laddered U.S. Equity Equal Weight Buffer ETF Investment Risks link:presentationLink link:definitionLink link:calculationLink 1310006 - Disclosure - FT Vest Laddered U.S. Equity Equal Weight Buffer ETF Performance Management link:presentationLink link:definitionLink link:calculationLink 1320010 - Disclosure - FT Vest Laddered U.S. Equity Equal Weight Buffer ETF Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 1320020 - Disclosure - FT Vest Laddered U.S. Equity Equal Weight Buffer ETF Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 1320030 - Disclosure - FT Vest Laddered U.S. Equity Equal Weight Buffer ETF Expense Example link:presentationLink link:definitionLink link:calculationLink 1320040 - Disclosure - FT Vest Laddered U.S. Equity Equal Weight Buffer ETF Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 1320045 - Disclosure - FT Vest Laddered U.S. Equity Equal Weight Buffer ETF Risks Data link:presentationLink link:definitionLink link:calculationLink 1320050 - Disclosure - FT Vest Laddered U.S. Equity Equal Weight Buffer ETF Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1320060 - Disclosure - FT Vest Laddered U.S. Equity Equal Weight Buffer ETF Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1320070 - Disclosure - FT Vest Laddered U.S. Equity Equal Weight Buffer ETF Market Index Performance link:presentationLink link:definitionLink link:calculationLink 1310000 - Disclosure - FT Vest Laddered U.S. Equity Equal Weight Buffer ETF N-1A Cover link:presentationLink link:definitionLink link:calculationLink 1310001 - Disclosure - FT Vest Laddered U.S. Equity Equal Weight Buffer ETF N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 1410002 - Disclosure - FT Vest Laddered U.S. Equity Uncapped Accelerator ETF Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 1410003 - Disclosure - FT Vest Laddered U.S. Equity Uncapped Accelerator ETF Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 1410004 - Disclosure - FT Vest Laddered U.S. Equity Uncapped Accelerator ETF Investment Strategy link:presentationLink link:definitionLink link:calculationLink 1410005 - Disclosure - FT Vest Laddered U.S. Equity Uncapped Accelerator ETF Investment Risks link:presentationLink link:definitionLink link:calculationLink 1410006 - Disclosure - FT Vest Laddered U.S. Equity Uncapped Accelerator ETF Performance Management link:presentationLink link:definitionLink link:calculationLink 1420010 - Disclosure - FT Vest Laddered U.S. Equity Uncapped Accelerator ETF Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 1420020 - Disclosure - FT Vest Laddered U.S. Equity Uncapped Accelerator ETF Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 1420030 - Disclosure - FT Vest Laddered U.S. Equity Uncapped Accelerator ETF Expense Example link:presentationLink link:definitionLink link:calculationLink 1420040 - Disclosure - FT Vest Laddered U.S. Equity Uncapped Accelerator ETF Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 1420045 - Disclosure - FT Vest Laddered U.S. Equity Uncapped Accelerator ETF Risks Data link:presentationLink link:definitionLink link:calculationLink 1420050 - Disclosure - FT Vest Laddered U.S. Equity Uncapped Accelerator ETF Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1420060 - Disclosure - FT Vest Laddered U.S. Equity Uncapped Accelerator ETF Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1420070 - Disclosure - FT Vest Laddered U.S. Equity Uncapped Accelerator ETF Market Index Performance link:presentationLink link:definitionLink link:calculationLink 1410000 - Disclosure - FT Vest Laddered U.S. Equity Uncapped Accelerator ETF N-1A Cover link:presentationLink link:definitionLink link:calculationLink 1410001 - Disclosure - FT Vest Laddered U.S. Equity Uncapped Accelerator ETF N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 1510002 - Disclosure - FT Vest Laddered Emerging Markets Buffer ETF Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 1510003 - Disclosure - FT Vest Laddered Emerging Markets Buffer ETF Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 1510004 - Disclosure - FT Vest Laddered Emerging Markets Buffer ETF Investment Strategy link:presentationLink link:definitionLink link:calculationLink 1510005 - Disclosure - FT Vest Laddered Emerging Markets Buffer ETF Investment Risks link:presentationLink link:definitionLink link:calculationLink 1510006 - Disclosure - FT Vest Laddered Emerging Markets Buffer ETF Performance Management link:presentationLink link:definitionLink link:calculationLink 1520010 - Disclosure - FT Vest Laddered Emerging Markets Buffer ETF Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 1520020 - Disclosure - FT Vest Laddered Emerging Markets Buffer ETF Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 1520030 - Disclosure - FT Vest Laddered Emerging Markets Buffer ETF Expense Example link:presentationLink link:definitionLink link:calculationLink 1520040 - Disclosure - FT Vest Laddered Emerging Markets Buffer ETF Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 1520045 - Disclosure - FT Vest Laddered Emerging Markets Buffer ETF Risks Data link:presentationLink link:definitionLink link:calculationLink 1520050 - Disclosure - FT Vest Laddered Emerging Markets Buffer ETF Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1520060 - Disclosure - FT Vest Laddered Emerging Markets Buffer ETF Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1520070 - Disclosure - FT Vest Laddered Emerging Markets Buffer ETF Market Index Performance link:presentationLink link:definitionLink link:calculationLink 1510000 - Disclosure - FT Vest Laddered Emerging Markets Buffer ETF N-1A Cover link:presentationLink link:definitionLink link:calculationLink 1510001 - Disclosure - FT Vest Laddered Emerging Markets Buffer ETF N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 1610002 - Disclosure - FT Vest Laddered Max Buffer ETF Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 1610003 - Disclosure - FT Vest Laddered Max Buffer ETF Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 1610004 - Disclosure - FT Vest Laddered Max Buffer ETF Investment Strategy link:presentationLink link:definitionLink link:calculationLink 1610005 - Disclosure - FT Vest Laddered Max Buffer ETF Investment Risks link:presentationLink link:definitionLink link:calculationLink 1610006 - Disclosure - FT Vest Laddered Max Buffer ETF Performance Management link:presentationLink link:definitionLink link:calculationLink 1620010 - Disclosure - FT Vest Laddered Max Buffer ETF Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 1620020 - Disclosure - FT Vest Laddered Max Buffer ETF Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 1620030 - Disclosure - FT Vest Laddered Max Buffer ETF Expense Example link:presentationLink link:definitionLink link:calculationLink 1620040 - Disclosure - FT Vest Laddered Max Buffer ETF Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 1620045 - Disclosure - FT Vest Laddered Max Buffer ETF Risks Data link:presentationLink link:definitionLink link:calculationLink 1620050 - Disclosure - FT Vest Laddered Max Buffer ETF Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1620060 - Disclosure - FT Vest Laddered Max Buffer ETF Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1620070 - Disclosure - FT Vest Laddered Max Buffer ETF Market Index Performance link:presentationLink link:definitionLink link:calculationLink 1610000 - Disclosure - FT Vest Laddered Max Buffer ETF N-1A Cover link:presentationLink link:definitionLink link:calculationLink 1610001 - Disclosure - FT Vest Laddered Max Buffer ETF N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 1710002 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - January Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 1710003 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - January Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 1710004 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - January Investment Strategy link:presentationLink link:definitionLink link:calculationLink 1710005 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - January Investment Risks link:presentationLink link:definitionLink link:calculationLink 1710006 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - January Performance Management link:presentationLink link:definitionLink link:calculationLink 1720010 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - January Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 1720020 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - January Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 1720030 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - January Expense Example link:presentationLink link:definitionLink link:calculationLink 1720040 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - January Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 1720045 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - January Risks Data link:presentationLink link:definitionLink link:calculationLink 1720050 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - January Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1720060 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - January Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1720070 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - January Market Index Performance link:presentationLink link:definitionLink link:calculationLink 1710000 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - January N-1A Cover link:presentationLink link:definitionLink link:calculationLink 1710001 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - January N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 1810002 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - April Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 1810003 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - April Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 1810004 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - April Investment Strategy link:presentationLink link:definitionLink link:calculationLink 1810005 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - April Investment Risks link:presentationLink link:definitionLink link:calculationLink 1810006 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - April Performance Management link:presentationLink link:definitionLink link:calculationLink 1820010 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - April Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 1820020 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - April Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 1820030 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - April Expense Example link:presentationLink link:definitionLink link:calculationLink 1820040 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - April Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 1820045 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - April Risks Data link:presentationLink link:definitionLink link:calculationLink 1820050 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - April Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1820060 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - April Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1820070 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - April Market Index Performance link:presentationLink link:definitionLink link:calculationLink 1810000 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - April N-1A Cover link:presentationLink link:definitionLink link:calculationLink 1810001 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - April N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 1910002 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - October Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 1910003 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - October Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 1910004 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - October Investment Strategy link:presentationLink link:definitionLink link:calculationLink 1910005 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - October Investment Risks link:presentationLink link:definitionLink link:calculationLink 1910006 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - October Performance Management link:presentationLink link:definitionLink link:calculationLink 1920010 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - October Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 1920020 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - October Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 1920030 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - October Expense Example link:presentationLink link:definitionLink link:calculationLink 1920040 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - October Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 1920045 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - October Risks Data link:presentationLink link:definitionLink link:calculationLink 1920050 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - October Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1920060 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - October Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 1920070 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - October Market Index Performance link:presentationLink link:definitionLink link:calculationLink 1910000 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - October N-1A Cover link:presentationLink link:definitionLink link:calculationLink 1910001 - Disclosure - FT Vest U.S. Equity Buffer & Digital Return ETF - October N-1A Supplement link:presentationLink link:definitionLink link:calculationLink 2010002 - Disclosure - First Trust Flexible Income ETF Investment Objectives and Goals link:presentationLink link:definitionLink link:calculationLink 2010003 - Disclosure - First Trust Flexible Income ETF Fees and Expenses link:presentationLink link:definitionLink link:calculationLink 2010004 - Disclosure - First Trust Flexible Income ETF Investment Strategy link:presentationLink link:definitionLink link:calculationLink 2010005 - Disclosure - First Trust Flexible Income ETF Investment Risks link:presentationLink link:definitionLink link:calculationLink 2010006 - Disclosure - First Trust Flexible Income ETF Performance Management link:presentationLink link:definitionLink link:calculationLink 2020010 - Disclosure - First Trust Flexible Income ETF Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 2020020 - Disclosure - First Trust Flexible Income ETF Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 2020030 - Disclosure - First Trust Flexible Income ETF Expense Example link:presentationLink link:definitionLink link:calculationLink 2020040 - Disclosure - First Trust Flexible Income ETF Expense Example, No Redemption link:presentationLink link:definitionLink link:calculationLink 2020045 - Disclosure - First Trust Flexible Income ETF Risks Data link:presentationLink link:definitionLink link:calculationLink 2020050 - Disclosure - First Trust Flexible Income ETF Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 2020060 - Disclosure - First Trust Flexible Income ETF Average Annual Total Returns link:presentationLink link:definitionLink link:calculationLink 2020070 - Disclosure - First Trust Flexible Income ETF Market Index Performance link:presentationLink link:definitionLink link:calculationLink 2010000 - Disclosure - First Trust Flexible Income ETF N-1A Cover link:presentationLink link:definitionLink link:calculationLink 2010001 - Disclosure - First Trust Flexible Income ETF N-1A Supplement link:presentationLink link:definitionLink link:calculationLink FT Vest U.S. Equity Max Buffer ETF - January S000088212 [Member] C000254276 [Member] Absence Of An Active Market Risk [Member] Buffer Change 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] Large Capitalization Companies Risk [Member] Management Risk [Member] Market Risk [Member] Risk Nondiversified [Member] Operational Risk [Member] Options Risk [Member] Premium Discount Risk [Member] Special Tax Risk [Member] Target Outcome Period Risk [Member] Tax Risk [Member] Trading Issues Risk [Member] Underlying ETF Concentration Risk [Member] Underlying ETF Equity Risk [Member] Underlying ETF Risk [Member] FT Vest U.S. Equity Max Buffer ETF - February S000088211 [Member] C000254275 [Member] FT Vest U.S. Equity Max Buffer ETF - March S000084310 [Member] C000248655 [Member] S&P 500® Index (reflects no deduction for fees, expenses or taxes)[Member] FT Vest U.S. Equity Max Buffer ETF - April S000088209 [Member] C000254273 [Member] FT Vest U.S. Equity Max Buffer ETF - May S000088213 [Member] C000254277 [Member] FT Vest U.S. Equity Max Buffer ETF - June S000085355 [Member] C000250354 [Member] FT Vest U.S. Equity Max Buffer ETF - July S000085836 [Member] C000251231 [Member] FT Vest U.S. Equity Max Buffer ETF - August S000086490 [Member] C000252052 [Member] FT Vest U.S. Equity Max Buffer ETF - September S000086491 [Member] C000252053 [Member] FT Vest U.S. Equity Max Buffer ETF - October S000088215 [Member] C000254279 [Member] FT Vest U.S. Equity Max Buffer ETF - November S000088214 [Member] C000254278 [Member] FT Vest U.S. Equity Max Buffer ETF - December S000088210 [Member] C000254274 [Member] FT Vest Laddered U.S. Equity Equal Weight Buffer ETF S000101908 [Member] C000272281 [Member] Concentrated Investment Risk [Member] Conflict Of Interest Risk [Member] Portfolio Turnover Risk [Member] RSP Equity Risk [Member] RSP Risk [Member] Significant Exposure Risk [Member] Tax Risk From Investment In Other Investment Companies [Member] Underlying ETF Exposure Risk [Member] FT Vest Laddered U.S. Equity Uncapped Accelerator ETF S000101906 [Member] C000272279 [Member] Accelerated Return Risk [Member] SPY Equity Risk [Member] Spy Risk [Member] Upside Rate of Return Risk [Member] FT Vest Laddered Emerging Markets Buffer ETF S000102075 [Member] C000272535 [Member] Asia Risk [Member] EEM Equity Risk [Member] EEM Risk [Member] Mid Capitalization Companies Risk [Member] South Korea Risk [Member] Taiwan Risk [Member] Variable Interest Entities Risk [Member] FT Vest Laddered Max Buffer ETF S000093230 [Member] C000261392 [Member] Market Fluctuation Risk [Member] FT Vest U.S. Equity Buffer & Digital Return ETF - January S000095247 [Member] FT Vest U.S. Equity Buffer & Digital Return ETF - January C000263951 [Member] Digital Return Change Risk [Member] Digital Return Risk [Member] Valuation Risk [Member] FT Vest U.S. Equity Buffer & Digital Return ETF - April S000095246 [Member] FT Vest U.S. Equity Buffer & Digital Return ETF - April C000263950 [Member] FT Vest U.S. Equity Buffer & Digital Return ETF - October S000095248 [Member] FT Vest U.S. Equity Buffer & Digital Return ETF - October C000263952 [Member] First Trust Flexible Income ETF S000102073 [Member] C000272533 [Member] Bloomberg US Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)[Member] Morningstar® LSTA® US Leveraged Loan Index (reflects no deduction for fees, expenses or taxes)[Member] Asset Backed Securities Risk [Member] Authorized Participant Concentration Risk [Member] Bank Loans Risk [Member] Call Risk [Member] CLO Risk [Member] Contingent Convertible Securities Risk [Member] Covenant Lite Loans Risk [Member] Credit Default Swaps Risk [Member] Credit Rating Agency Risk [Member] Credit Risk [Member] Currency Risk [Member] Debt Securities Risk [Member] Defaulted Securities Risk [Member] Derivatives Risk [Member] Distressed Securities Risk [Member] Emerging Markets Risk [Member] Extension Risk [Member] Floating Rate Debt Instruments Risk [Member] Forward Contracts Risk [Member] Futures Contracts Risk [Member] High Yield Securities Risk [Member] Hybrid Capital Securities Risk [Member] Income Risk [Member] Inflation Risk [Member] Interest And Principal Only Securities Risk [Member] Interest Rate Risk [Member] Leverage Risk [Member] Liquidity Risk [Member] Market Maker Risk [Member] Money Market Short Term Securities Risk [Member] Mortgage Related Securities Risk [Member] Non Agency Securities Risk [Member] Non US Securities Risk [Member] OTC Derivatives Risk [Member] Preferred Securities Risk [Member] Prepayment Risk [Member] Restricted Securities Risk [Member] Senior Loan Risk [Member] Short Sales Risk [Member] Swap Agreements Risk [Member] When Issued TBA And Delayed Delivery Transactions Risk [Member] Zero Coupon Bond Risk [Member]