PRINCIPAL TRANSACTIONS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Principal transactions revenue
Principal transactions revenue	$ 2,304	$ 4,157	$ 6,217	$ 9,418
Interest rate risks
Principal transactions revenue
Principal transactions revenue	530	1,847	1,964	3,757
Foreign exchange risks
Principal transactions revenue
Principal transactions revenue	965	1,114	1,927	2,109
Equity risks
Principal transactions revenue
Principal transactions revenue	358	103	1,203	921
Commodity and other risks
Principal transactions revenue
Principal transactions revenue	393	365	593	760
Credit products and risks
Principal transactions revenue
Principal transactions revenue	$ 58	$ 728	$ 530	$ 1,871