COMMISSIONS AND FEES; ADMINISTRATION AND OTHER FIDUCIARY FEES - Commissions and Fees Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Commissions and fees
Commissions and fees revenue	$ 13,672	$ 11,385	$ 11,746
Investment banking
Commissions and fees
Commissions and fees revenue	6,007	4,483	3,767
Brokerage commissions
Commissions and fees
Commissions and fees revenue	3,236	2,960	2,612
Credit card and bank card income, interchange fees
Commissions and fees
Commissions and fees revenue	9,821	8,004	9,843
Credit card and bank card income, card-related loan fees
Commissions and fees
Commissions and fees revenue	695	649	778
Credit card and bank card income, card rewards and partner payments
Commissions and fees
Commissions and fees revenue	(10,235)	(8,673)	(9,574)
Deposit-related fees
Commissions and fees
Commissions and fees revenue	1,331	1,334	1,518
Transactional service fees
Commissions and fees
Commissions and fees revenue	1,098	974	947
Corporate finance
Commissions and fees
Commissions and fees revenue	709	457	616
Insurance distribution revenue
Commissions and fees
Commissions and fees revenue	473	503	536
Insurance premiums
Commissions and fees
Commissions and fees revenue	94	125	186
Loan servicing
Commissions and fees
Commissions and fees revenue	98	137	154
Other
Commissions and fees
Commissions and fees revenue	345	432	363
Overdraft fees
Commissions and fees
Commissions and fees revenue	107	100	127
Commissions and fees
Commissions and fees
Revenue not accounted for under ASC 606	(8,516)	(7,160)	(7,695)
ICG
Commissions and fees
Commissions and fees revenue	11,441	9,327	8,806
ICG | Investment banking
Commissions and fees
Commissions and fees revenue	6,007	4,483	3,767
ICG | Brokerage commissions
Commissions and fees
Commissions and fees revenue	2,080	1,986	1,771
ICG | Credit card and bank card income, interchange fees
Commissions and fees
Commissions and fees revenue	817	703	1,222
ICG | Credit card and bank card income, card-related loan fees
Commissions and fees
Commissions and fees revenue	28	23	60
ICG | Credit card and bank card income, card rewards and partner payments
Commissions and fees
Commissions and fees revenue	(405)	(380)	(691)
ICG | Deposit-related fees
Commissions and fees
Commissions and fees revenue	1,044	958	1,048
ICG | Transactional service fees
Commissions and fees
Commissions and fees revenue	1,003	886	824
ICG | Corporate finance
Commissions and fees
Commissions and fees revenue	709	457	616
ICG | Insurance distribution revenue
Commissions and fees
Commissions and fees revenue	11	11	12
ICG | Insurance premiums
Commissions and fees
Commissions and fees revenue	0	0	0
ICG | Loan servicing
Commissions and fees
Commissions and fees revenue	43	82	78
ICG | Other
Commissions and fees
Commissions and fees revenue	104	118	99
GCB
Commissions and fees
Commissions and fees revenue	2,212	2,029	2,916
GCB | Investment banking
Commissions and fees
Commissions and fees revenue	0	0	0
GCB | Brokerage commissions
Commissions and fees
Commissions and fees revenue	1,156	974	841
GCB | Credit card and bank card income, interchange fees
Commissions and fees
Commissions and fees revenue	9,004	7,301	8,621
GCB | Credit card and bank card income, card-related loan fees
Commissions and fees
Commissions and fees revenue	667	626	718
GCB | Credit card and bank card income, card rewards and partner payments
Commissions and fees
Commissions and fees revenue	(9,830)	(8,293)	(8,883)
GCB | Deposit-related fees
Commissions and fees
Commissions and fees revenue	287	376	470
GCB | Transactional service fees
Commissions and fees
Commissions and fees revenue	95	88	123
GCB | Corporate finance
Commissions and fees
Commissions and fees revenue	0	0	0
GCB | Insurance distribution revenue
Commissions and fees
Commissions and fees revenue	462	492	524
GCB | Insurance premiums
Commissions and fees
Commissions and fees revenue	94	125	186
GCB | Loan servicing
Commissions and fees
Commissions and fees revenue	40	30	55
GCB | Other
Commissions and fees
Commissions and fees revenue	237	310	261
Corporate/Other
Commissions and fees
Commissions and fees revenue	19	29	24
Corporate/Other | Investment banking
Commissions and fees
Commissions and fees revenue	0	0	0
Corporate/Other | Brokerage commissions
Commissions and fees
Commissions and fees revenue	0	0	0
Corporate/Other | Credit card and bank card income, interchange fees
Commissions and fees
Commissions and fees revenue	0	0	0
Corporate/Other | Credit card and bank card income, card-related loan fees
Commissions and fees
Commissions and fees revenue	0	0	0
Corporate/Other | Credit card and bank card income, card rewards and partner payments
Commissions and fees
Commissions and fees revenue	0	0	0
Corporate/Other | Deposit-related fees
Commissions and fees
Commissions and fees revenue	0	0	0
Corporate/Other | Transactional service fees
Commissions and fees
Commissions and fees revenue	0	0	0
Corporate/Other | Corporate finance
Commissions and fees
Commissions and fees revenue	0	0	0
Corporate/Other | Insurance distribution revenue
Commissions and fees
Commissions and fees revenue	0	0	0
Corporate/Other | Insurance premiums
Commissions and fees
Commissions and fees revenue	0	0	0
Corporate/Other | Loan servicing
Commissions and fees
Commissions and fees revenue	15	25	21
Corporate/Other | Other
Commissions and fees
Commissions and fees revenue	$ 4	$ 4	$ 3