PRINCIPAL TRANSACTIONS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Principal transactions revenue
Principal transactions revenue	$ 2,233	$ 2,508	$ 8,450	$ 11,926
Interest rate risks
Principal transactions revenue
Principal transactions revenue	461	993	2,424	4,751
Foreign exchange risks
Principal transactions revenue
Principal transactions revenue	924	960	2,851	3,069
Equity risks
Principal transactions revenue
Principal transactions revenue	666	157	1,869	1,078
Commodity and other risks
Principal transactions revenue
Principal transactions revenue	252	248	844	1,007
Credit products and risks
Principal transactions revenue
Principal transactions revenue	$ (70)	$ 150	$ 462	$ 2,021