GUARANTEES AND COMMITMENTS - Performance Risk (Details) - USD ($) $ in Billions	Sep. 30, 2024	Dec. 31, 2023
Guarantor Obligations
Maximum potential amount of future payments	$ 533.7	$ 412.1
Classified based on internal and external credit ratings
Guarantor Obligations
Maximum potential amount of future payments	87.8	90.8
Investment grade
Guarantor Obligations
Maximum potential amount of future payments	67.4	70.5
Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	19.4	18.5
Not rated
Guarantor Obligations
Maximum potential amount of future payments	1.0	1.8
Financial standby letters of credit
Guarantor Obligations
Maximum potential amount of future payments	79.1	81.3
Financial standby letters of credit | Classified based on internal and external credit ratings
Guarantor Obligations
Maximum potential amount of future payments	79.1	81.3
Financial standby letters of credit | Investment grade
Guarantor Obligations
Maximum potential amount of future payments	67.4	70.5
Financial standby letters of credit | Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	11.7	10.8
Financial standby letters of credit | Not rated
Guarantor Obligations
Maximum potential amount of future payments	0.0	0.0
Loans sold with recourse
Guarantor Obligations
Maximum potential amount of future payments	1.0	1.8
Loans sold with recourse | Classified based on internal and external credit ratings
Guarantor Obligations
Maximum potential amount of future payments	1.0	1.8
Loans sold with recourse | Investment grade
Guarantor Obligations
Maximum potential amount of future payments	0.0	0.0
Loans sold with recourse | Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	0.0	0.0
Loans sold with recourse | Not rated
Guarantor Obligations
Maximum potential amount of future payments	1.0	1.8
Other
Guarantor Obligations
Maximum potential amount of future payments	7.8	7.7
Other | Classified based on internal and external credit ratings
Guarantor Obligations
Maximum potential amount of future payments	7.7	7.7
Other | Investment grade
Guarantor Obligations
Maximum potential amount of future payments	0.0	0.0
Other | Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	7.7	7.7
Other | Not rated
Guarantor Obligations
Maximum potential amount of future payments	$ 0.0	$ 0.0