GOODWILL AND INTANGIBLE ASSETS - Changes in Goodwill (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023
Goodwill
Balance of goodwill at beginning of period	$ 19,998	$ 19,882	$ 19,691
Foreign currency translation	(169)	116	191
Balance of goodwill at end of period	19,829	19,998	19,882
Institutional Clients Group
Goodwill
Balance of goodwill at beginning of period	9,041	9,028	8,986
Foreign currency translation	(132)	13	42
Balance of goodwill at end of period	8,909	9,041	9,028
Personal Banking and Wealth Management
Goodwill
Balance of goodwill at beginning of period	9,858	9,810	9,741
Foreign currency translation	(17)	48	69
Balance of goodwill at end of period	9,841	9,858	9,810
Legacy Franchises
Goodwill
Balance of goodwill at beginning of period	1,099	1,044	964
Foreign currency translation	(20)	55	80
Balance of goodwill at end of period	$ 1,079	$ 1,099	$ 1,044