FAIR VALUE MEASUREMENT (Details 6) (USD $)	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Assets.
Investments	$ 287,339,000,000	$ 294,463,000,000
Federal funds sold and securities borrowed or purchased under agreements to resell	167,748,000,000	160,589,000,000
Loans	4,988,000,000	5,287,000,000
Other financial assets	13,669,000,000	13,299,000,000
Liabilities;
Deposits	933,762,000,000	930,560,000,000
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase and securities loaned	124,854,000,000	116,689,000,000
Long-term debt	28,151,000,000	29,764,000,000
Other financial liabilities	2,721,000,000	2,910,000,000
Allowance for loan losses	23,727,000,000	25,455,000,000	29,020,000,000	30,115,000,000
Lease finance receivables	2,700,000,000	2,800,000,000
Loans, excluding lease finance receivables
Fair value measurements additional disclosures
Aggregate carrying value in excess of (less than) fair value	7,700,000,000	9,700,000,000
Consumer
Assets.
Loans	1,202,000,000	1,231,000,000
Fair value measurements additional disclosures
Aggregate carrying value in excess of (less than) fair value	5,100,000,000
Corporate
Assets.
Loans	3,786,000,000	4,056,000,000
Fair value measurements additional disclosures
Aggregate carrying value in excess of (less than) fair value	2,600,000,000
Level 1
Assets.
Investments	3,900,000,000	3,000,000,000
Other financial assets	9,800,000,000	11,400,000,000
Level 2
Assets.
Investments	13,100,000,000	14,300,000,000
Federal funds sold and securities borrowed or purchased under agreements to resell	96,100,000,000	94,800,000,000
Loans	4,500,000,000	4,200,000,000
Other financial assets	168,300,000,000	128,300,000,000
Liabilities;
Deposits	752,900,000,000	748,700,000,000
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase and securities loaned	92,600,000,000	94,400,000,000
Long-term debt	183,000,000,000	177,000,000,000
Other financial liabilities	25,800,000,000	31,100,000,000
Level 3
Assets.
Investments	1,100,000,000	1,100,000,000
Federal funds sold and securities borrowed or purchased under agreements to resell	6,600,000,000	5,900,000,000
Loans	602,700,000,000	608,000,000,000
Other financial assets	56,000,000,000	53,100,000,000
Liabilities;
Deposits	177,800,000,000	178,700,000,000
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase and securities loaned	4,600,000,000	100,000,000
Long-term debt	30,700,000,000	38,300,000,000
Other financial liabilities	113,700,000,000	107,900,000,000
Carrying value
Assets.
Investments	17,500,000,000	17,900,000,000
Federal funds sold and securities borrowed or purchased under agreements to resell	102,700,000,000	100,700,000,000
Loans	614,900,000,000	621,900,000,000
Other financial assets	234,100,000,000	192,800,000,000
Liabilities;
Deposits	932,200,000,000	929,100,000,000
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase and securities loaned	97,200,000,000	94,500,000,000
Long-term debt	206,200,000,000	209,700,000,000
Other financial liabilities	139,500,000,000	139,000,000,000
Fair value
Assets.
Investments	18,100,000,000	18,400,000,000
Federal funds sold and securities borrowed or purchased under agreements to resell	102,700,000,000	100,700,000,000
Loans	607,200,000,000	612,200,000,000
Other financial assets	234,100,000,000	192,800,000,000
Liabilities;
Deposits	930,700,000,000	927,400,000,000
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase and securities loaned	97,200,000,000	94,500,000,000
Long-term debt	213,700,000,000	215,300,000,000
Other financial liabilities	139,500,000,000	139,000,000,000
Fair value | Level 3
Fair value measurements additional disclosures
Estimated fair values of corporate unfunded lending commitments	$ 4,600,000,000	$ 4,900,000,000