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FT Vest Emerging Markets Buffer ETF - September Average Annual Total Returns
12 Months Ended 15 Months Ended
May 31, 2026
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
MSCI Emerging Markets Index (reflects no deduction for fees, expenses or taxes)[Member]        
Prospectus [Line Items]        
Average Annual Return, Percent   32.90% 33.57% 22.83%
FT Vest Emerging Markets Buffer ETF - September        
Prospectus [Line Items]        
Average Annual Return, Percent     20.94% 14.29%
Performance Inception Date Sep. 20, 2024      
FT Vest Emerging Markets Buffer ETF - September | After Taxes on Distributions        
Prospectus [Line Items]        
Average Annual Return, Percent     20.94% 14.29%
FT Vest Emerging Markets Buffer ETF - September | After Taxes on Distributions and Sales        
Prospectus [Line Items]        
Average Annual Return, Percent     12.39% 10.94%