LOANS - Consumer Loans Gross Credit Losses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 1,879	$ 1,212	$ 3,513	$ 2,452
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 1,793	$ 1,155	3,388	$ 2,347
Consumer | Residential mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
2023			0
2022			1
2021			0
2020			1
2019			3
Prior			20
Total			25
Consumer | Home equity loans (pre-reset)
Financing Receivable, Credit Quality Indicator [Line Items]
Total			2
Consumer | Home equity loans (post-reset)
Financing Receivable, Credit Quality Indicator [Line Items]
Total			0
Consumer | Home equity term loans
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving loans converted to term loans			1
Consumer | Home equity loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total			3
Consumer | Credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
Revolving loans converted to term loans			87
Total			2,925
Consumer | Credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
Total			3,012
Consumer | Personal, small business and other
Financing Receivable, Credit Quality Indicator [Line Items]
2023			69
2022			89
2021			56
2020			23
2019			27
Prior			84
Total			$ 348