TRADING ACCOUNT ASSETS AND LIABILITIES (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Trading account assets and Trading account liabilities
Trading account assets	$ 320,637	$ 317,272
Trading account liabilities	148,851	129,054
Mortgage-backed securities
Trading account assets and Trading account liabilities
Trading account assets	35,117	34,989
U.S. government-sponsored agency guaranteed
Trading account assets and Trading account liabilities
Trading account assets	27,631	27,127
Prime
Trading account assets and Trading account liabilities
Trading account assets	1,391	1,514
Alt-A
Trading account assets and Trading account liabilities
Trading account assets	1,234	1,502
Subprime
Trading account assets and Trading account liabilities
Trading account assets	1,351	2,036
Non-U.S. residential
Trading account assets and Trading account liabilities
Trading account assets	550	1,052
Commercial
Trading account assets and Trading account liabilities
Trading account assets	2,960	1,758
U.S. Treasury and federal agency securities
Trading account assets and Trading account liabilities
Trading account assets	18,604	23,586
U.S. Treasury
Trading account assets and Trading account liabilities
Trading account assets	15,469	20,168
Agency obligations
Trading account assets and Trading account liabilities
Trading account assets	3,135	3,418
State and municipal securities
Trading account assets and Trading account liabilities
Trading account assets	6,269	7,493
Foreign government securities
Trading account assets and Trading account liabilities
Trading account assets	102,890	88,311
Corporate
Trading account assets and Trading account liabilities
Trading account assets	43,664	51,422
Derivatives, assets
Trading account assets and Trading account liabilities
Trading account assets	60,265	50,213
Equity securities
Trading account assets and Trading account liabilities
Trading account assets	31,395	37,436
Asset-based financing
Trading account assets and Trading account liabilities
Trading account assets	7,003	8,606
Other debt securities
Trading account assets and Trading account liabilities
Trading account assets	15,430	15,216
Securities sold, not yet purchased
Trading account assets and Trading account liabilities
Trading account liabilities	87,597	69,324
Derivatives, liabilities
Trading account assets and Trading account liabilities
Trading account liabilities	$ 61,254	$ 59,730