v3.26.1
FT Vest META & Target Income ETF N-1A Cover
Sep. 11, 2026
Prospectus [Line Items]  
Document Type 485BPOS
Amendment Flag false
Registrant Name First Trust Exchange-Traded Fund IV
Entity Central Index Key 0001517936
Entity Investment Company Type N-1A
Document Period End Date Sep. 11, 2026
Prospectus Date Sep. 14, 2026