LOANS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
LOANS
Number of loan categories	2
Loans
Loans, net of unearned income	$ 646,364		$ 655,464
Consumer
Loans
Total loans	395,554		409,089
Net unearned income	(378)		(418)
Loans, net of unearned income	395,176		408,671
Loans sold and/or reclassified to held-for-sale	3,700	600
In U.S. offices | Consumer
Loans
Total loans	243,644		256,763
In U.S. offices | Consumer | Mortgage and real estate
Loans
Total loans	120,768		125,946
In U.S. offices | Consumer | Installment, revolving credit and other
Loans
Total loans	12,955		14,070
In U.S. offices | Consumer | Credit cards
Loans
Total loans	104,535		111,403
In U.S. offices | Consumer | Commercial and industrial
Loans
Total loans	5,386		5,344
In offices outside the U.S. | Consumer
Loans
Total loans	151,910		152,326
In offices outside the U.S. | Consumer | Mortgage and real estate
Loans
Total loans	54,717		54,709
In offices outside the U.S. | Consumer | Installment, revolving credit and other
Loans
Total loans	34,020		33,958
In offices outside the U.S. | Consumer | Credit cards
Loans
Total loans	39,522		40,653
In offices outside the U.S. | Consumer | Commercial and industrial
Loans
Total loans	22,906		22,225
In offices outside the U.S. | Consumer | Lease financing
Loans
Total loans	$ 745		$ 781