PRINCIPAL TRANSACTIONS (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Principal transactions revenue
Principal transactions revenue	$ 3,913	$ 5,261
Interest rate risks
Principal transactions revenue
Principal transactions revenue	1,433	1,838
Foreign exchange risks
Principal transactions revenue
Principal transactions revenue	962	1,066
Equity risks
Principal transactions revenue
Principal transactions revenue	845	819
Commodity and other risks
Principal transactions revenue
Principal transactions revenue	200	395
Credit products and risks
Principal transactions revenue
Principal transactions revenue	$ 473	$ 1,143