PRINCIPAL TRANSACTIONS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Principal transactions revenue
Principal transactions revenue	$ 4,157	$ 1,874	$ 9,418	$ 4,678
Interest rate risks
Principal transactions revenue
Principal transactions revenue	1,843	1,320	3,820	3,038
Foreign exchange risks
Principal transactions revenue
Principal transactions revenue	1,114	427	2,109	900
Equity risks
Principal transactions revenue
Principal transactions revenue	102	(1)	921	455
Commodity and other risks
Principal transactions revenue
Principal transactions revenue	370	89	697	208
Credit products and risks
Principal transactions revenue
Principal transactions revenue	$ 728	$ 39	$ 1,871	$ 77