PRINCIPAL TRANSACTIONS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Principal transactions revenue
Principal transactions revenue	$ 8,892	$ 8,905	$ 8,940
Interest rate risks
Principal transactions revenue
Principal transactions revenue	5,990	5,178	5,304
Foreign exchange risks
Principal transactions revenue
Principal transactions revenue	1,650	1,398	2,435
Equity risks
Principal transactions revenue
Principal transactions revenue	872	1,336	525
Commodity and other risks
Principal transactions revenue
Principal transactions revenue	516	669	425
Credit products and risks
Principal transactions revenue
Principal transactions revenue	$ (136)	$ 324	$ 251