COMMISSIONS AND FEES; ADMINISTRATION AND OTHER FIDUCIARY FEES - Administration and Other Fiduciary Fees (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Commissions and fees
Total administration and other fiduciary fees	$ 1,023	$ 1,022	$ 1,989	$ 1,983
Custody fees
Commissions and fees
Total administration and other fiduciary fees	530	503	1,002	960
Custody fees | ICG
Commissions and fees
Total administration and other fiduciary fees	506	476	952	908
Custody fees | PBWM
Commissions and fees
Total administration and other fiduciary fees	22	24	45	45
Custody fees | Legacy Franchises
Commissions and fees
Total administration and other fiduciary fees	2	3	5	7
Fiduciary fees
Commissions and fees
Total administration and other fiduciary fees	343	372	693	731
Fiduciary fees | ICG
Commissions and fees
Total administration and other fiduciary fees	68	61	133	123
Fiduciary fees | PBWM
Commissions and fees
Total administration and other fiduciary fees	196	200	401	392
Fiduciary fees | Legacy Franchises
Commissions and fees
Total administration and other fiduciary fees	79	111	159	216
Guarantee fees
Commissions and fees
Total administration and other fiduciary fees	150	147	294	292
Guarantee fees | ICG
Commissions and fees
Total administration and other fiduciary fees	134	133	266	266
Guarantee fees | PBWM
Commissions and fees
Total administration and other fiduciary fees	14	11	24	22
Guarantee fees | Legacy Franchises
Commissions and fees
Total administration and other fiduciary fees	2	3	4	4
Administration and other fiduciary fees
Commissions and fees
Total administration and other fiduciary fees	1,023	1,022	1,989	1,983
Revenue not accounted for under ASC 606, revenue from contracts with customers	150	147	294	292
Administration and other fiduciary fees | ICG
Commissions and fees
Total administration and other fiduciary fees	708	670	1,351	1,297
Administration and other fiduciary fees | PBWM
Commissions and fees
Total administration and other fiduciary fees	232	235	470	459
Administration and other fiduciary fees | Legacy Franchises
Commissions and fees
Total administration and other fiduciary fees	$ 83	$ 117	$ 168	$ 227