SECURITIZATIONS AND VARIABLE INTEREST ENTITIES (Details 7) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013		Dec. 31, 2013
Re-securitizations
Balance at beginning of period									$ 2,718,000,000
Balance at end of period	2,093,000,000				2,093,000,000				2,718,000,000
Mortgage servicing rights
Classification of Securitizations
Fair value of capitalized mortgage servicing rights	2,100,000,000		2,600,000,000		2,100,000,000		2,600,000,000
Principal amount of loans and other financial instruments	232,000,000,000		295,000,000,000		232,000,000,000		295,000,000,000
Re-securitizations
Balance at beginning of period	2,282,000,000		2,524,000,000		2,718,000,000		1,942,000,000
Originations	52,000,000		167,000,000		151,000,000		543,000,000
Changes in fair value of MSRs due to changes in inputs and assumptions	(11,000,000)		11,000,000		(186,000,000)		481,000,000
Other changes	(108,000,000)	[1]	(121,000,000)	[1]	(333,000,000)	[1]	(384,000,000)	[1]
Sale of MSRs	(122,000,000)		(1,000,000)		(257,000,000)		(2,000,000)
Balance at end of period	2,093,000,000		2,580,000,000		2,093,000,000		2,580,000,000
Servicing fees	159,000,000		196,000,000		491,000,000		611,000,000
Late fees	5,000,000		12,000,000		20,000,000		31,000,000
Ancillary fees	11,000,000		27,000,000		47,000,000		79,000,000
Total MSR fees	175,000,000		235,000,000		558,000,000		721,000,000
Mortgage securitizations - Non-agency-sponsored
Re-securitizations
Original par value of securities transferred to re-securitization entities	81,000,000		284,000,000		470,000,000		680,000,000
Fair value of re-securitizations deals in which the entity holds a retained interest	375,000,000				375,000,000				425,000,000
Market value of retained interest related to re-securitization transaction	46,000,000				46,000,000				131,000,000
Original par value of re-securitizations deals in which the entity holds a retained interest	4,700,000,000				4,700,000,000				6,100,000,000
Senior interests
Re-securitizations
Fair value of re-securitizations deals in which the entity holds a retained interest	10,000,000				10,000,000				58,000,000
Subordinated interests
Re-securitizations
Fair value of re-securitizations deals in which the entity holds a retained interest	365,000,000				365,000,000				367,000,000
U.S. government-sponsored agency guaranteed
Re-securitizations
Fair value of re-securitizations deals in which the entity holds a retained interest	1,300,000,000				1,300,000,000				1,500,000,000
Market value of retained interest related to re-securitization transaction	998,000,000				998,000,000				1,200,000,000
Securities transferred to re-securitization entities	5,400,000,000		5,300,000,000		16,700,000,000		20,100,000,000
Original fair value of re-securitizations deals in which the entity holds a retained interest	69,300,000,000				69,300,000,000				75,500,000,000
Citicorp | Mortgage servicing rights
Classification of Securitizations
Fair value of capitalized mortgage servicing rights	$ 1,900,000,000		$ 2,000,000,000		$ 1,900,000,000		$ 2,000,000,000

[1] Represents changes due to customer payments and passage of time.