v3.25.3
Form N-1A Cover
Apr. 30, 2025
Prospectus [Line Items]  
Document Type 485BPOS
Amendment Flag false
Registrant Name AMG FUNDS IV
Entity Central Index Key 0000912036
Entity Investment Company Type N-1A
Document Period End Date Apr. 30, 2025
Prospectus Date Dec. 08, 2025