CONTINGENCIES (Details) (USD $)				2 Months Ended	0 Months Ended	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Dec. 31, 2007 Arbitration brought by the Abu Dhabi Investment Authority	Sep. 30, 2013 Mortgage-Related Litigation and Other Matters item	Apr. 30, 2013 Residential Mortgage-Backed Securities Investor Actions and Repurchase Claims In Re Citigroup Inc. Securities Litigation	Sep. 30, 2013 KIKOs CKI item	Sep. 13, 2013 Interchange Fees Litigation item
CONTINGENCIES
Possible loss, high end of the range	$ 5,000,000,000	$ 5,000,000,000
Contingencies
Number of objectors have filed notices of appeal				3
Aggregate original purchase amount					8,000,000,000
Aggregate original purchase amount of the purchases covered by tolling agreements					6,000,000,000
Investments in entity by counterparties and investors' alleged arbitration			7,500,000,000
Number civil lawsuits filed by small and medium-sized enterprises						99	2
Number of decision rendered at district court level						84
Decisions favorable to entity						64
Number of decisions awarded to plaintiff for portion of damages sought						20
Contingent loss as claimed against the company						30,000,000
Number of decisions appealed at the high court						62
Number of cases decided at the high court						23
Number of decisions favorable to the entity in the high court						14
Number of decisions awarded by the high court to the plaintiff for a portion of damages sought						9
Increase in damages awarded						$ 9,600,000
Number of decisions appealed at the Supreme court						8