COMMISSIONS AND FEES; ADMINISTRATION AND OTHER FIDUCIARY FEES - Commissions and Fees Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Commissions and fees
Total commissions and fees	$ 2,568	$ 3,670
Investment banking
Commissions and fees
Total commissions and fees	908	1,624
Brokerage commissions
Commissions and fees
Total commissions and fees	767	942
Interchange fees
Commissions and fees
Total commissions and fees	2,560	2,064
Card-related loan fees
Commissions and fees
Total commissions and fees	154	182
Card rewards and partner payments
Commissions and fees
Total commissions and fees	(2,789)	(2,171)
Deposit-related fees
Commissions and fees
Total commissions and fees	344	329
Transactional service fees
Commissions and fees
Total commissions and fees	284	265
Corporate finance
Commissions and fees
Total commissions and fees	119	158
Insurance distribution revenue
Commissions and fees
Total commissions and fees	88	135
Insurance premiums
Commissions and fees
Total commissions and fees	26	20
Loan servicing
Commissions and fees
Total commissions and fees	26	23
Other
Commissions and fees
Total commissions and fees	81	99
Overdraft fees
Commissions and fees
Total commissions and fees	32	24
Commissions and fees
Commissions and fees
Revenue not accounted for under ASC 606, revenue from contracts with customers	(2,427)	(1,749)
ICG
Commissions and fees
Total commissions and fees	2,147	2,884
ICG | Investment banking
Commissions and fees
Total commissions and fees	908	1,624
ICG | Brokerage commissions
Commissions and fees
Total commissions and fees	460	521
ICG | Interchange fees
Commissions and fees
Total commissions and fees	240	158
ICG | Card-related loan fees
Commissions and fees
Total commissions and fees	9	5
ICG | Card rewards and partner payments
Commissions and fees
Total commissions and fees	(118)	(75)
ICG | Deposit-related fees
Commissions and fees
Total commissions and fees	267	242
ICG | Transactional service fees
Commissions and fees
Total commissions and fees	254	232
ICG | Corporate finance
Commissions and fees
Total commissions and fees	116	155
ICG | Insurance distribution revenue
Commissions and fees
Total commissions and fees	0	0
ICG | Insurance premiums
Commissions and fees
Total commissions and fees	0	0
ICG | Loan servicing
Commissions and fees
Total commissions and fees	12	12
ICG | Other
Commissions and fees
Total commissions and fees	(1)	10
PBWM
Commissions and fees
Total commissions and fees	80	315
PBWM | Investment banking
Commissions and fees
Total commissions and fees	0	0
PBWM | Brokerage commissions
Commissions and fees
Total commissions and fees	240	289
PBWM | Interchange fees
Commissions and fees
Total commissions and fees	2,099	1,694
PBWM | Card-related loan fees
Commissions and fees
Total commissions and fees	64	78
PBWM | Card rewards and partner payments
Commissions and fees
Total commissions and fees	(2,499)	(1,956)
PBWM | Deposit-related fees
Commissions and fees
Total commissions and fees	59	55
PBWM | Transactional service fees
Commissions and fees
Total commissions and fees	4	5
PBWM | Corporate finance
Commissions and fees
Total commissions and fees	3	3
PBWM | Insurance distribution revenue
Commissions and fees
Total commissions and fees	52	83
PBWM | Insurance premiums
Commissions and fees
Total commissions and fees	1	1
PBWM | Loan servicing
Commissions and fees
Total commissions and fees	10	7
PBWM | Other
Commissions and fees
Total commissions and fees	47	56
Legacy Franchises
Commissions and fees
Total commissions and fees	341	471
Legacy Franchises | Investment banking
Commissions and fees
Total commissions and fees	0	0
Legacy Franchises | Brokerage commissions
Commissions and fees
Total commissions and fees	67	132
Legacy Franchises | Interchange fees
Commissions and fees
Total commissions and fees	221	212
Legacy Franchises | Card-related loan fees
Commissions and fees
Total commissions and fees	81	99
Legacy Franchises | Card rewards and partner payments
Commissions and fees
Total commissions and fees	(172)	(140)
Legacy Franchises | Deposit-related fees
Commissions and fees
Total commissions and fees	18	32
Legacy Franchises | Transactional service fees
Commissions and fees
Total commissions and fees	26	28
Legacy Franchises | Corporate finance
Commissions and fees
Total commissions and fees	0	0
Legacy Franchises | Insurance distribution revenue
Commissions and fees
Total commissions and fees	36	52
Legacy Franchises | Insurance premiums
Commissions and fees
Total commissions and fees	25	19
Legacy Franchises | Loan servicing
Commissions and fees
Total commissions and fees	4	4
Legacy Franchises | Other
Commissions and fees
Total commissions and fees	35	33
Corporate/Other
Commissions and fees
Total commissions and fees	0	0
Corporate/Other | Investment banking
Commissions and fees
Total commissions and fees	0	0
Corporate/Other | Brokerage commissions
Commissions and fees
Total commissions and fees	0	0
Corporate/Other | Interchange fees
Commissions and fees
Total commissions and fees	0	0
Corporate/Other | Card-related loan fees
Commissions and fees
Total commissions and fees	0	0
Corporate/Other | Card rewards and partner payments
Commissions and fees
Total commissions and fees	0	0
Corporate/Other | Deposit-related fees
Commissions and fees
Total commissions and fees	0	0
Corporate/Other | Transactional service fees
Commissions and fees
Total commissions and fees	0	0
Corporate/Other | Corporate finance
Commissions and fees
Total commissions and fees	0	0
Corporate/Other | Insurance distribution revenue
Commissions and fees
Total commissions and fees	0	0
Corporate/Other | Insurance premiums
Commissions and fees
Total commissions and fees	0	0
Corporate/Other | Loan servicing
Commissions and fees
Total commissions and fees	0	0
Corporate/Other | Other
Commissions and fees
Total commissions and fees	$ 0	$ 0