INVESTMENTS (Details 6) (USD $)			3 Months Ended			1 Months Ended	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Jun. 30, 2012 Akbank	Mar. 31, 2012 Akbank	Mar. 31, 2013 Akbank	Sep. 30, 2012 Morgan Stanley Smith Barney joint venture	Mar. 31, 2013 Morgan Stanley Smith Barney joint venture	Sep. 30, 2012 Morgan Stanley Smith Barney joint venture	Sep. 17, 2012 Morgan Stanley Smith Barney joint venture	Sep. 16, 2012 Morgan Stanley Smith Barney joint venture	Sep. 11, 2012 Morgan Stanley Smith Barney joint venture	Mar. 31, 2013 Mortgage-backed securities	Dec. 31, 2012 Mortgage-backed securities	Mar. 31, 2013 State and municipal securities	Dec. 31, 2012 State and municipal securities	Mar. 31, 2013 Foreign government	Dec. 31, 2012 Foreign government	Mar. 31, 2013 All Other	Dec. 31, 2012 All Other
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount;
Due within 1 year, carrying value														$ 12,000,000	$ 14,000,000
After 1 but within 5 years, carrying value												45,000,000	69,000,000	32,000,000	36,000,000	3,816,000,000	2,987,000,000	724,000,000	728,000,000
After 5 but within 10 years, carrying value												44,000,000	54,000,000	55,000,000	58,000,000
After 10 years, carrying value												3,662,000,000	4,586,000,000	1,172,000,000	1,097,000,000			494,000,000	501,000,000
Total carrying value	10,056,000,000	10,130,000,000										3,751,000,000	4,709,000,000	1,271,000,000	1,205,000,000	3,816,000,000	2,987,000,000	1,218,000,000	1,229,000,000
Held-to-maturity Securities, Debt Maturities, Fair Value;
Due within 1 year, fair value														13,000,000	15,000,000
After 1 but within 5 years, fair value												44,000,000	67,000,000	33,000,000	37,000,000	3,866,000,000	2,987,000,000	828,000,000	802,000,000
After 5 but within 10 years, fair value												45,000,000	54,000,000	60,000,000	62,000,000
After 10 years, fair value												4,015,000,000	4,977,000,000	1,207,000,000	1,143,000,000			506,000,000	500,000,000
Total fair value	10,617,000,000	10,644,000,000										4,104,000,000	5,098,000,000	1,313,000,000	1,257,000,000	3,866,000,000	2,987,000,000	1,334,000,000	1,302,000,000
Carrying value of equity method investment										11,300,000,000
Maximum equity method investment ownership percentage				10.00%
Percentage of ownership interest held				20.00%		35.00%	35.00%	35.00%		49.00%
Proceed from selling 14% interest in the joint venture						1,890,000,000
Total charge to earnings related to the investment, pretax								4,700,000,000
Total charge to earnings related to the investment, after-tax								2,900,000,000
Ownership interest sold by entity (as a percent)			10.10%			14.00%	14.00%
Percentage of ownership interest held in the investment which is recorded within marketable equity securities available-for-sale					9.90%
Impairment charge related to investment, after-tax				763,000,000
Impairment charge related to investment, pre-tax				1,181,000,000
100% value of the joint venture											13,500,000,000
Agreed selling price for the remaining 35% interest in the joint venture							4,725,000,000
Deposit transferred to the buyer of the investment at no premium						4,500,000,000
Premium on deposits									0
Loss on sale of investment, before tax			424,000,000					1,300,000,000
Loss on sale of investment, after tax			274,000,000					800,000,000
Other-than-temporary impairment of the carrying value, pretax								3,400,000,000
Other-than-temporary impairment of the carrying value, after-tax								$ 2,100,000,000