INTEREST REVENUE AND EXPENSE (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Interest revenue
Loan interest, including fees	$ 12,171	$ 12,671	$ 36,628	$ 37,728
Deposits with banks	296	423	994	1,342
Federal funds sold and securities borrowed or purchased under agreements to resell	825	948	2,670	2,689
Investments, including dividends	1,882	1,924	5,646	6,461
Trading account assets	1,616	2,073	5,008	6,293
Other interest	144	106	414	373
Total interest revenue	16,934	18,145	51,360	54,886
Interest expense
Deposits	1,912	2,228	5,820	6,472
Federal funds purchased and securities loaned or sold under agreements to repurchase	713	796	2,161	2,466
Trading account liabilities	46	91	151	343
Short-term borrowings	173	155	564	493
Long-term debt	2,177	2,761	7,211	8,748
Total interest expense	5,021	6,031	15,907	18,522
Net interest revenue	11,913	12,114	35,453	36,364
Provision for loan losses	2,511	3,049	7,924	9,129
Net interest revenue after provision for loan losses	9,402	9,065	27,529	27,235
Insurance fees and charges	$ 290	$ 387	$ 959	$ 974