SECURITIZATIONS AND VARIABLE INTEREST ENTITIES (Details 3) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Variable Interest Entity
Cash and due from banks (including segregated cash and other deposits)	$ 33,380,000,000	$ 29,885,000,000	$ 31,150,000,000	$ 36,453,000,000
Trading account assets	278,180,000,000	285,928,000,000
Investments	312,900,000,000	308,980,000,000
Total loans, net	645,298,000,000	645,824,000,000
Other assets	125,591,000,000	125,266,000,000
Total assets	1,894,736,000,000	1,880,382,000,000
Long-term debt	222,747,000,000	221,116,000,000
Consolidated VIEs
Variable Interest Entity
Cash and due from banks (including segregated cash and other deposits)	200,000,000	400,000,000
Trading account assets	900,000,000	1,000,000,000
Investments	11,600,000,000	10,900,000,000
Total loans, net	92,200,000,000	91,900,000,000
Other assets	800,000,000	1,300,000,000
Total assets	105,700,000,000	105,500,000,000
Short-term borrowings	21,100,000,000	24,300,000,000
Long-term debt	38,100,000,000	34,800,000,000
Other liabilities	1,100,000,000	1,000,000,000
Total Liabilities	60,300,000,000	60,100,000,000
Significant unconsolidated VIE assets
Variable Interest Entity
Trading account assets	4,900,000,000	5,200,000,000
Investments	3,900,000,000	4,100,000,000
Total loans, net	18,900,000,000	18,900,000,000
Other assets	2,600,000,000	2,700,000,000
Total assets	30,300,000,000	30,900,000,000
Citicorp | Consolidated VIEs
Variable Interest Entity
Cash and due from banks (including segregated cash and other deposits)	200,000,000	200,000,000
Trading account assets	900,000,000	1,000,000,000
Investments	11,600,000,000	10,900,000,000
Total loans, net	89,200,000,000	83,200,000,000
Other assets	800,000,000	1,100,000,000
Total assets	102,700,000,000	96,400,000,000
Short-term borrowings	21,100,000,000	24,300,000,000
Long-term debt	37,000,000,000	32,800,000,000
Other liabilities	1,000,000,000	900,000,000
Total Liabilities	59,100,000,000	58,000,000,000
Citicorp | Significant unconsolidated VIE assets
Variable Interest Entity
Trading account assets	4,500,000,000	4,800,000,000
Investments	3,700,000,000	3,700,000,000
Total loans, net	18,400,000,000	18,300,000,000
Other assets	2,100,000,000	2,200,000,000
Total assets	28,700,000,000	29,000,000,000
Citi Holdings
Variable Interest Entity
Total assets	114,000,000,000	117,000,000,000
Citi Holdings | Consolidated VIEs
Variable Interest Entity
Cash and due from banks (including segregated cash and other deposits)		200,000,000
Total loans, net	3,000,000,000	8,700,000,000
Other assets		200,000,000
Total assets	3,000,000,000	9,100,000,000
Long-term debt	1,100,000,000	2,000,000,000
Other liabilities	100,000,000	100,000,000
Total Liabilities	1,200,000,000	2,100,000,000
Citi Holdings | Significant unconsolidated VIE assets
Variable Interest Entity
Trading account assets	400,000,000	400,000,000
Investments	200,000,000	400,000,000
Total loans, net	500,000,000	600,000,000
Other assets	500,000,000	500,000,000
Total assets	$ 1,600,000,000	$ 1,900,000,000