v3.25.1
Document and Entity Information
Jun. 03, 2025
Document And Entity Information [Line Items]  
Amendment Flag false
Entity Central Index Key 0001004434
Document Type 8-K
Document Period End Date Jun. 03, 2025
Entity Registrant Name AFFILIATED MANAGERS GROUP, INC.
Entity Incorporation State Country Code DE
Entity File Number 001-13459
Entity Tax Identification Number 04-3218510
Entity Address, Address Line One 777 South Flagler Drive
Entity Address, City or Town West Palm Beach
Entity Address, State or Province FL
Entity Address, Postal Zip Code 33401
City Area Code (800)
Local Phone Number 345-1100
Written Communications false
Soliciting Material false
Pre Commencement Tender Offer false
Pre Commencement Issuer Tender Offer false
Entity Emerging Growth Company false
Common Stock [Member]  
Document And Entity Information [Line Items]  
Security 12b Title Common Stock ($0.01 par value)
Trading Symbol AMG
Security Exchange Name NYSE
Five Point Eight Seventy Five Junior Subordinated Notes Due 2059 [Member]  
Document And Entity Information [Line Items]  
Security 12b Title 5.875% Junior Subordinated Notes due 2059
Trading Symbol MGR
Security Exchange Name NYSE
Four Point Seventy Five Junior Subordinated Notes Due 2060 [Member]  
Document And Entity Information [Line Items]  
Security 12b Title 4.750% Junior Subordinated Notes due 2060
Trading Symbol MGRB
Security Exchange Name NYSE
Four Point Two Junior Subordinated Notes Due 2061 [Member]  
Document And Entity Information [Line Items]  
Security 12b Title 4.200% Junior Subordinated Notes due 2061
Trading Symbol MGRD
Security Exchange Name NYSE
Six Point Seventy Five Junior Subordinated Notes Due 2064 [Member]  
Document And Entity Information [Line Items]  
Security 12b Title 6.750% Junior Subordinated Notes due 2064
Trading Symbol MGRE
Security Exchange Name NYSE