LOANS - Corporate Loans Gross Credit Losses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 1,634	$ 1,240
Corporate
Financing Receivable, Credit Quality Indicator [Line Items]
2023	1
2022	0
2021	0
2020	0
2019	0
Prior	0
Revolving line of credit arrangement	38
Total	39	$ 48
Corporate | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
2023	1
2022	0
2021	0
2020	0
2019	0
Prior	0
Revolving line of credit arrangement	35
Total	36
Corporate | Financial institutions
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0
2022	0
2021	0
2020	0
2019	0
Prior	0
Revolving line of credit arrangement	0
Total	0
Corporate | Mortgage and real estate
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0
2022	0
2021	0
2020	0
2019	0
Prior	0
Revolving line of credit arrangement	0
Total	0
Corporate | Other
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0
2022	0
2021	0
2020	0
2019	0
Prior	0
Revolving line of credit arrangement	3
Total	$ 3