COMMISSIONS AND FEES; ADMINISTRATION AND OTHER FIDUCIARY FEES - Commissions and Fees Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Commissions and fees
Commissions and fees revenue	$ 8,905	$ 9,175	$ 13,672
Investment banking
Commissions and fees
Commissions and fees revenue	2,676	3,084	6,007
Brokerage commissions
Commissions and fees
Commissions and fees revenue	2,316	2,546	3,236
Revenue recognized	448	538	639
Credit and bank card income, interchange fees
Commissions and fees
Commissions and fees revenue	11,996	11,505	9,821
Credit and bank card income, card-related loan fees
Commissions and fees
Commissions and fees revenue	475	589	695
Credit and bank card income, card rewards and partner payments
Commissions and fees
Commissions and fees revenue	(12,513)	(12,336)	(10,235)
Deposit-related fees
Commissions and fees
Commissions and fees revenue	1,254	1,274	1,331
Transactional service fees
Commissions and fees
Commissions and fees revenue	1,323	1,169	1,098
Corporate finance
Commissions and fees
Commissions and fees revenue	439	458	709
Insurance distribution revenue
Commissions and fees
Commissions and fees revenue	321	346	473
Revenue recognized	188	201	260
Insurance premiums
Commissions and fees
Commissions and fees revenue	97	91	94
Loan servicing
Commissions and fees
Commissions and fees revenue	100	103	98
Other
Commissions and fees
Commissions and fees revenue	421	346	345
Overdraft fees
Commissions and fees
Commissions and fees revenue	0	59	107
Commissions and fees
Commissions and fees
Revenue not accounted for under ASC 606	$ (11,367)	$ (11,008)	$ (8,516)