SECURITIZATIONS AND VARIABLE INTEREST ENTITIES (Details 8) (USD $)			3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Asset-based financing	Mar. 31, 2012 Asset-based financing	Mar. 31, 2013 Citicorp	Dec. 31, 2012 Citicorp	Mar. 31, 2013 Citicorp Asset-based financing	Mar. 31, 2013 Citi Holdings	Dec. 31, 2012 Citi Holdings	Mar. 31, 2013 Citi Holdings Collateralized debt obligations (CDOs)	Mar. 31, 2013 Citi Holdings Collateralized loan obligations (CLOs)	Mar. 31, 2013 Citi Holdings Asset-based financing	Mar. 31, 2013 Commercial and other real estate Citicorp Asset-based financing	Mar. 31, 2013 Commercial and other real estate Citi Holdings Asset-based financing	Mar. 31, 2013 Corporate loans Citicorp Asset-based financing	Mar. 31, 2013 Corporate loans Citi Holdings Asset-based financing	Mar. 31, 2013 Hedge funds and equities Citicorp Asset-based financing	Mar. 31, 2013 Airplanes, ships and other assets Citicorp Asset-based financing	Mar. 31, 2013 Airplanes, ships and other assets Citi Holdings Asset-based financing
Variable Interest Entity
Total unconsolidated VIE assets	$ 477,174,000,000	$ 499,481,000,000			$ 345,094,000,000	$ 354,493,000,000	$ 37,000,000,000	$ 132,080,000,000	$ 144,988,000,000			$ 3,800,000,000	$ 13,800,000,000	$ 800,000,000	$ 2,000,000,000	$ 400,000,000	$ 600,000,000	$ 20,600,000,000	$ 2,600,000,000
Maximum exposure to unconsolidated VIEs	45,128,000,000	45,971,000,000			41,063,000,000	41,644,000,000	17,100,000,000	4,065,000,000	4,327,000,000			1,100,000,000	3,400,000,000	300,000,000	1,400,000,000	300,000,000	400,000,000	11,900,000,000	500,000,000
Cash flows received on retained interest and other net cash flows			300,000,000	900,000,000
Sensitivity analysis of fair value of interests continued to be held by transferor
Carrying value of retained interests							$ 1,421,000,000			$ 16,000,000	$ 203,000,000	$ 338,000,000