SECURITIZATIONS AND VARIABLE INTEREST ENTITIES (Details 4) (USD $)	6 Months Ended			3 Months Ended		6 Months Ended				3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014 Citicorp	Dec. 31, 2013 Citicorp	Jun. 30, 2014 Citicorp Credit card securitizations	Jun. 30, 2013 Citicorp Credit card securitizations	Jun. 30, 2014 Citicorp Credit card securitizations	Jun. 30, 2013 Citicorp Credit card securitizations	Jun. 30, 2014 Citi Holdings	Dec. 31, 2013 Citi Holdings	Jun. 30, 2014 Citi Holdings Credit card securitizations	Jun. 30, 2013 Citi Holdings Credit card securitizations	Jun. 30, 2014 Citi Holdings Credit card securitizations	Jun. 30, 2013 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		37,700,000,000	32,300,000,000
Retained by Citigroup as trust-issued securities		9,400,000,000	8,100,000,000					1,300,000,000	1,300,000,000
Retained by Citigroup via non-certificated interests		12,900,000,000	12,100,000,000
Total ownership interests in principal amount of trust credit card receivables		60,000,000,000	52,500,000,000					1,300,000,000	1,300,000,000
Cash Flows Between Transferor and Transferee
Proceeds from new securitizations				2,400,000,000	2,500,000,000	6,700,000,000	2,500,000,000			0	0	100,000,000	0
Pay down of maturing notes				$ (1,300,000,000)	$ (800,000,000)	$ (1,300,000,000)	$ (1,600,000,000)			$ 0	$ 0	$ 0	$ (100,000,000)