LOANS (Details 5) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Loans
Loans, net of unearned income	$ 646,364	$ 655,464
Corporate
Loans
Total loans	252,036	247,590
Net unearned income	(848)	(797)
Loans, net of unearned income	251,188	246,793
Corporate | Commercial and industrial
Loans
Loans, net of unearned income	112,637	108,776
Corporate | Financial institutions
Loans
Loans, net of unearned income	53,339	54,317
Corporate | Mortgage and real estate
Loans
Loans, net of unearned income	31,686	31,070
Corporate | Lease financing
Loans
Loans, net of unearned income	1,962	2,015
In U.S. offices | Corporate
Loans
Total loans	105,624	103,705
In U.S. offices | Corporate | Commercial and industrial
Loans
Total loans	28,558	26,985
In U.S. offices | Corporate | Financial institutions
Loans
Total loans	16,500	18,159
In U.S. offices | Corporate | Mortgage and real estate
Loans
Total loans	25,576	24,705
In U.S. offices | Corporate | Installment, revolving credit and other
Loans
Total loans	33,621	32,446
In U.S. offices | Corporate | Lease financing
Loans
Total loans	1,369	1,410
In offices outside the U.S. | Corporate
Loans
Total loans	146,412	143,885
In offices outside the U.S. | Corporate | Commercial and industrial
Loans
Total loans	85,258	82,939
In offices outside the U.S. | Corporate | Financial institutions
Loans
Total loans	38,332	37,739
In offices outside the U.S. | Corporate | Mortgage and real estate
Loans
Total loans	6,231	6,485
In offices outside the U.S. | Corporate | Installment, revolving credit and other
Loans
Total loans	14,733	14,958
In offices outside the U.S. | Corporate | Lease financing
Loans
Total loans	593	605
In offices outside the U.S. | Corporate | Government and official institutions
Loans
Total loans	$ 1,265	$ 1,159