GUARANTEES AND COMMITMENTS - Performance Risk (Details) - USD ($) $ in Billions	Sep. 30, 2023	Dec. 31, 2022
Guarantor Obligations
Maximum potential amount of future payments	$ 421.9	$ 386.1
Classified based on internal and external credit ratings
Guarantor Obligations
Maximum potential amount of future payments	126.8	99.8
Investment grade
Guarantor Obligations
Maximum potential amount of future payments	91.7	77.9
Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	33.3	18.9
Not rated
Guarantor Obligations
Maximum potential amount of future payments	1.8	3.0
Financial standby letters of credit
Guarantor Obligations
Maximum potential amount of future payments	85.3	89.6
Financial standby letters of credit | Classified based on internal and external credit ratings
Guarantor Obligations
Maximum potential amount of future payments	85.3	89.6
Financial standby letters of credit | Investment grade
Guarantor Obligations
Maximum potential amount of future payments	74.3	77.9
Financial standby letters of credit | Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	11.0	10.4
Financial standby letters of credit | Not rated
Guarantor Obligations
Maximum potential amount of future payments	0.0	1.3
Loans sold with recourse
Guarantor Obligations
Maximum potential amount of future payments	1.8	1.7
Loans sold with recourse | Classified based on internal and external credit ratings
Guarantor Obligations
Maximum potential amount of future payments	1.8	1.7
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	1.8	1.7
Other
Guarantor Obligations
Maximum potential amount of future payments	39.7	8.5
Other | Classified based on internal and external credit ratings
Guarantor Obligations
Maximum potential amount of future payments	39.7	8.5
Other | Investment grade
Guarantor Obligations
Maximum potential amount of future payments	17.4	0.0
Other | Non-investment grade
Guarantor Obligations
Maximum potential amount of future payments	22.3	8.5
Other | Not rated
Guarantor Obligations
Maximum potential amount of future payments	$ 0.0	$ 0.0