DISCONTINUED OPERATIONS AND SIGNIFICANT DISPOSALS (Details) (USD $)	3 Months Ended				9 Months Ended				0 Months Ended	3 Months Ended				9 Months Ended					1 Months Ended	3 Months Ended				9 Months Ended			12 Months Ended		3 Months Ended				9 Months Ended				3 Months Ended	9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013		Dec. 20, 2013 Brazil Creditcard	Sep. 30, 2014 Brazil Creditcard		Sep. 30, 2013 Brazil Creditcard		Sep. 30, 2014 Brazil Creditcard		Sep. 30, 2013 Brazil Creditcard		Dec. 20, 2013 Brazil Creditcard	Feb. 28, 2013 Citi Capital Advisors Business	Sep. 30, 2014 Citi Capital Advisors Business		Sep. 30, 2013 Citi Capital Advisors Business		Sep. 30, 2014 Citi Capital Advisors Business		Sep. 30, 2013 Citi Capital Advisors Business	Dec. 31, 2013 Citi Capital Advisors Business transaction company		Sep. 30, 2014 Egg Banking PLC		Sep. 30, 2013 Egg Banking PLC		Sep. 30, 2014 Egg Banking PLC		Sep. 30, 2013 Egg Banking PLC		Sep. 30, 2013 German retail banking operations	Sep. 30, 2014 German retail banking operations
Discontinued operations
Amount to be received on sale of discontinued operation																		$ 1,240,000,000
After tax gain on sale of discontinued operations	0		6,000,000		0		62,000,000		325,000,000
Results of Discontinued Operations
Total revenues, net of interest expense	2,000,000	[1]	231,000,000	[1]	75,000,000	[1]	811,000,000	[1]		1,000,000	[1]	223,000,000	[1]	70,000,000	[1]	738,000,000	[1]			0	[1]	8,000,000	[1]	0	[1]		73,000,000	[1]	1,000,000	[1]	0	[1]	5,000,000	[1]	0	[1]
Income (loss) from discontinued operations	(25,000,000)		33,000,000		12,000,000		(19,000,000)			(4,000,000)		36,000,000		65,000,000		143,000,000				(4,000,000)		(21,000,000)		(8,000,000)			(152,000,000)		(17,000,000)		(9,000,000)		(45,000,000)		(37,000,000)		27,000,000
Gain (loss) on sale	0		6,000,000		0		62,000,000		206,000,000											0		6,000,000		0			62,000,000
Benefit (provision) for income taxes	(9,000,000)		(53,000,000)		13,000,000		(46,000,000)			(1,000,000)		12,000,000		12,000,000		49,000,000				(1,000,000)		(5,000,000)		(3,000,000)			(28,000,000)		(7,000,000)		(3,000,000)		(16,000,000)		(13,000,000)		(57,000,000)
Income (loss) from discontinued operations, net of taxes	(16,000,000)		92,000,000		(1,000,000)		89,000,000			(3,000,000)		24,000,000		53,000,000		94,000,000				(3,000,000)		(10,000,000)		(5,000,000)			(62,000,000)		(10,000,000)		(6,000,000)		(29,000,000)		(24,000,000)		85,000,000
Discontinued operations
Cash flows from operating activities					0		154,000,000							0		197,000,000								0		(43,000,000)
Cash flows from investing activities					0		(207,000,000)							0		(207,000,000)								0		0
Cash flows from financing activities					0		43,000,000							0		0								0		43,000,000
Net cash provided by (used in) discontinued operations					0		(10,000,000)							0		(10,000,000)								0		0
Number of transactions																											2
Number of management companies resulting from the sale of business																											2
Ownership interest (as a percent)																			24.90%
Residual costs associated with banking operations tax effect																																						$ 20,000,000

[1] Total revenues include gain or loss on sale, if applicable.