LOANS - Corporate Troubled Debt Restructurings (Details) - Corporate loans - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Financing Receivable, Modified [Line Items]
Total modifications balance	$ 141	$ 113	$ 308	$ 170
Commercial and industrial
Financing Receivable, Modified [Line Items]
Total modifications balance	50	66	131	121
Mortgage and real estate
Financing Receivable, Modified [Line Items]
Total modifications balance	91	47	177	49
Other
Financing Receivable, Modified [Line Items]
Total modifications balance	0	0	0	0
Term extension
Financing Receivable, Modified [Line Items]
Total modifications balance	141	111	308	143
Term extension | Commercial and industrial
Financing Receivable, Modified [Line Items]
Total modifications balance	50	65	131	95
Term extension | Mortgage and real estate
Financing Receivable, Modified [Line Items]
Total modifications balance	91	46	177	48
Term extension | Other
Financing Receivable, Modified [Line Items]
Total modifications balance	0	0	0	0
Combination: Term extension and payment delay(4)
Financing Receivable, Modified [Line Items]
Total modifications balance	0	2	0	27
Combination: Term extension and payment delay(4) | Commercial and industrial
Financing Receivable, Modified [Line Items]
Total modifications balance	0	1	0	26
Combination: Term extension and payment delay(4) | Mortgage and real estate
Financing Receivable, Modified [Line Items]
Total modifications balance	0	1	0	1
Combination: Term extension and payment delay(4) | Other
Financing Receivable, Modified [Line Items]
Total modifications balance	$ 0	$ 0	$ 0	$ 0