GOODWILL AND INTANGIBLE ASSETS (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Goodwill
Balance of goodwill at beginning of period	$ 26,152	$ 25,392
Goodwill acquired during the period	19
Goodwill disposed of during the period	(159)	(102)
Other	(599)	862
Balance of goodwill at end of period	25,413	26,152
Global Consumer Banking
Goodwill
Balance of goodwill at beginning of period	10,701	9,921
Other	(465)	780
Balance of goodwill at end of period	10,236	10,701
Institutional Clients Group
Goodwill
Balance of goodwill at beginning of period	10,826	10,689
Goodwill acquired during the period	19
Goodwill disposed of during the period	(6)
Other	(102)	137
Balance of goodwill at end of period	10,737	10,826
Citi Holdings
Goodwill
Balance of goodwill at beginning of period	4,625	4,782
Goodwill disposed of during the period	(153)	(102)
Other	(32)	(55)
Balance of goodwill at end of period	$ 4,440	$ 4,625