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LOANS - Consumer Loans Gross Credit Losses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 2,715	$ 1,879	$ 5,405	$ 3,513
Consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 2,586	$ 1,793	5,098	3,388
Consumer loans \| Residential mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
2024			0	0
2023			1	1
2022			0	0
2021			0	1
2020			0	3
Prior			22	20
Total			23	25
Consumer loans \| Home equity loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total			5	3
Consumer loans \| Home equity line of credit (pre-reset)
Financing Receivable, Credit Quality Indicator [Line Items]
Total			3	2
Consumer loans \| Home equity line of credit (post-reset)
Financing Receivable, Credit Quality Indicator [Line Items]
Total			1	0
Consumer loans \| Home equity term loans
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving loans converted to term loans			1	1
Consumer loans \| Credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving loans converted to term loans			119	87
Total			4,557	2,925
Consumer loans \| Credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
Total			4,676	3,012
Consumer loans \| Personal, small business and other
Financing Receivable, Credit Quality Indicator [Line Items]
2024			58	69
2023			100	89
2022			95	56
2021			37	23
2020			14	27
Prior			90	84
Total			$ 394	$ 348