VARIABLE INTEREST ENTITIES - Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022
Variable Interest Entity [Line Items]
Total Assets	$ 45,496	$ 43,725	$ 42,590
Total Liabilities	39,602	38,072
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Total Assets	166	157
Total Liabilities	119	118
Maximum Exposure to Loss	163	156
Trust preferred securities | Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Total Assets	3	1
Total Liabilities	73	72
Maximum Exposure to Loss	0	0
Affordable housing tax credit partnerships | Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Total Assets	122	123
Total Liabilities	40	37
Maximum Exposure to Loss	122	123
Other investments | Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Total Assets	41	33
Total Liabilities	6	9
Maximum Exposure to Loss	$ 41	$ 33