LOANS - Interest Income Recognized for Non-Accrual Consumer Loans (Details) - Consumer - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Financing Receivable, Nonaccrual [Line Items]
Interest income	$ 6	$ 4
Loans sold and/or reclassified to held-for-sale	1,800	7
In North America offices
Financing Receivable, Nonaccrual [Line Items]
Interest income	5	4
In offices outside North America
Financing Receivable, Nonaccrual [Line Items]
Interest income	1	0
Residential mortgages | In North America offices
Financing Receivable, Nonaccrual [Line Items]
Interest income	3	3
Residential mortgages | In offices outside North America
Financing Receivable, Nonaccrual [Line Items]
Interest income	1	0
Home equity loans | In North America offices
Financing Receivable, Nonaccrual [Line Items]
Interest income	2	1
Credit cards | In North America offices
Financing Receivable, Nonaccrual [Line Items]
Interest income	0	0
Credit cards | In offices outside North America
Financing Receivable, Nonaccrual [Line Items]
Interest income	0	0
Personal, small business and other | In North America offices
Financing Receivable, Nonaccrual [Line Items]
Interest income	0	0
Personal, small business and other | In offices outside North America
Financing Receivable, Nonaccrual [Line Items]
Interest income	$ 0	$ 0