LOANS - Corporate Loan Modifications to Borrowers Experiencing Financial Difficulty (Details) - Corporate - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Financing receivable impaired
Total modifications balance	$ 356
Commitments to lend	878	$ 1,200
Term extension
Financing receivable impaired
Total modifications balance	356
Combination: term extension and payment delay
Financing receivable impaired
Total modifications balance	0
Commercial and industrial
Financing receivable impaired
Total modifications balance	$ 251
Weighted- average term extension (months)	16 months
Commercial and industrial | Term extension
Financing receivable impaired
Total modifications balance	$ 251
Commercial and industrial | Combination: term extension and payment delay
Financing receivable impaired
Total modifications balance	0
Financial institutions
Financing receivable impaired
Total modifications balance	0
Financial institutions | Term extension
Financing receivable impaired
Total modifications balance	0
Financial institutions | Combination: term extension and payment delay
Financing receivable impaired
Total modifications balance	0
Mortgage and real estate
Financing receivable impaired
Total modifications balance	$ 105
Weighted- average term extension (months)	8 months
Mortgage and real estate | Term extension
Financing receivable impaired
Total modifications balance	$ 105
Mortgage and real estate | Combination: term extension and payment delay
Financing receivable impaired
Total modifications balance	0
Other
Financing receivable impaired
Total modifications balance	0
Other | Term extension
Financing receivable impaired
Total modifications balance	0
Other | Combination: term extension and payment delay
Financing receivable impaired
Total modifications balance	$ 0