PRINCIPAL TRANSACTIONS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Principal transactions revenue
Principal transactions revenue	$ 2,508	$ 2,802	$ 11,926	$ 7,480
Interest rate risks
Principal transactions revenue
Principal transactions revenue	971	1,370	4,791	3,057
Foreign exchange risks
Principal transactions revenue
Principal transactions revenue	960	794	3,069	3,095
Equity risks
Principal transactions revenue
Principal transactions revenue	157	418	1,078	809
Commodity and other risks
Principal transactions revenue
Principal transactions revenue	270	244	967	447
Credit products and risks
Principal transactions revenue
Principal transactions revenue	$ 150	$ (24)	$ 2,021	$ 72