SECURITIZATIONS AND VARIABLE INTEREST ENTITIES (Details 4) (USD $)	12 Months Ended			3 Months Ended	12 Months Ended			3 Months Ended	6 Months Ended	3 Months Ended			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Citicorp	Dec. 31, 2012 Citicorp	Mar. 31, 2013 Citicorp Credit card securitizations	Dec. 31, 2013 Citicorp Credit card securitizations	Dec. 31, 2012 Citicorp Credit card securitizations	Dec. 31, 2011 Citicorp Credit card securitizations	Mar. 31, 2013 Citibank Credit Card Master Trust (Master Trust) Credit card securitizations	Dec. 31, 2013 Citibank Credit Card Master Trust (Master Trust) Credit card securitizations	Mar. 31, 2013 Citibank OMNI Master Trust (Omni Trust) Credit card securitizations	Dec. 31, 2013 Citi Holdings	Dec. 31, 2012 Citi Holdings	Dec. 31, 2013 Citi Holdings Credit card securitizations	Dec. 31, 2012 Citi Holdings Credit card securitizations
Securitized credit card receivables
Gains (losses) recognized on the securitization	$ 0
Ownership interests in principal amount of trust credit card receivables
Sold to investors via trust-issued securities		32,300,000,000	22,900,000,000									100,000,000
Retained by Citigroup as trust-issued securities		8,100,000,000	11,900,000,000								1,300,000,000	1,400,000,000
Retained by Citigroup via non-certificated interests		12,100,000,000	44,600,000,000									200,000,000
Total ownership interests in principal amount of trust credit card receivables		52,500,000,000	79,400,000,000								1,300,000,000	1,700,000,000
Amount removed from or (added in) credit card receivables				27,000,000,000				12,000,000,000	(7,400,000,000)	15,000,000,000
Cash Flows Between Transferor and Transferee
Proceeds from new securitizations					15,200,000,000	2,400,000,000	3,900,000,000						200,000,000	400,000,000
Pay down of maturing notes					$ (11,200,000,000)	$ (21,700,000,000)	$ (20,500,000,000)						$ (100,000,000)