PRINCIPAL TRANSACTIONS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Principal transactions revenue
Principal transactions revenue	$ 2,888	$ 2,504
Interest rate contracts
Principal transactions revenue
Principal transactions revenue	1,390	1,502
Foreign exchange contracts
Principal transactions revenue
Principal transactions revenue	548	461
Equity contracts
Principal transactions revenue
Principal transactions revenue	138	158
Commodity and other contracts
Principal transactions revenue
Principal transactions revenue	224	119
Credit derivatives
Principal transactions revenue
Principal transactions revenue	588	264
Citicorp
Principal transactions revenue
Principal transactions revenue	2,817	2,541
Global Consumer Banking
Principal transactions revenue
Principal transactions revenue	195	210
Institutional Clients Group
Principal transactions revenue
Principal transactions revenue	2,607	2,473
Corporate/Other
Principal transactions revenue
Principal transactions revenue	15	(142)
Citi Holdings
Principal transactions revenue
Principal transactions revenue	$ 71	$ (37)