INVESTMENTS (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Investments summary
Securities available-for-sale, at fair value	$ 270,582	$ 265,204
Debt securities held-to-maturity	10,126	11,483
Non-marketable equity securities carried at fair value	8,842	8,836
Non-marketable equity securities carried at cost	7,773	7,890
Total investments	297,323	293,413
Securities available-for-sale
Fair value	270,582	265,204
Mortgage-backed securities
Investments summary
Securities available-for-sale, at fair value	52,134	51,025
Debt securities held-to-maturity	6,823	7,430
Securities available-for-sale
Amortized cost	50,935	49,649
Gross unrealized gains	1,292	1,464
Gross unrealized losses	93	88
Fair value	52,134	51,025
U.S. government-sponsored agency guaranteed
Investments summary
Securities available-for-sale, at fair value	45,102	45,781
Securities available-for-sale
Amortized cost	43,934	44,394
Gross unrealized gains	1,246	1,438
Gross unrealized losses	78	51
Fair value	45,102	45,781
Prime
Investments summary
Securities available-for-sale, at fair value	117	113
Debt securities held-to-maturity	280	287
Securities available-for-sale
Amortized cost	119	118
Gross unrealized gains	1	1
Gross unrealized losses	3	6
Fair value	117	113
Alt-A
Investments summary
Securities available-for-sale, at fair value	1	1
Debt securities held-to-maturity	2,876	3,328
Securities available-for-sale
Amortized cost	1	1
Fair value	1	1
Subprime
Investments summary
Debt securities held-to-maturity	230	336
Non-U.S. residential
Investments summary
Securities available-for-sale, at fair value	6,426	4,658
Debt securities held-to-maturity	2,947	2,967
Securities available-for-sale
Amortized cost	6,404	4,671
Gross unrealized gains	27	9
Gross unrealized losses	5	22
Fair value	6,426	4,658
Commercial
Investments summary
Securities available-for-sale, at fair value	488	472
Debt securities held-to-maturity	490	512
Securities available-for-sale
Amortized cost	477	465
Gross unrealized gains	18	16
Gross unrealized losses	7	9
Fair value	488	472
U.S. Treasury and federal agency securities
Investments summary
Securities available-for-sale, at fair value	89,174	85,138
Securities available-for-sale
Amortized cost	87,523	83,100
Gross unrealized gains	1,703	2,040
Gross unrealized losses	52	2
Fair value	89,174	85,138
U.S. Treasury
Investments summary
Securities available-for-sale, at fair value	54,915	50,229
Securities available-for-sale
Amortized cost	53,764	48,790
Gross unrealized gains	1,198	1,439
Gross unrealized losses	47
Fair value	54,915	50,229
Agency obligations
Investments summary
Securities available-for-sale, at fair value	34,259	34,909
Securities available-for-sale
Amortized cost	33,759	34,310
Gross unrealized gains	505	601
Gross unrealized losses	5	2
Fair value	34,259	34,909
State and municipal securities
Investments summary
Securities available-for-sale, at fair value	14,144	14,399
Debt securities held-to-maturity	1,286	1,327
Securities available-for-sale
Amortized cost	16,018	16,819
Gross unrealized gains	123	134
Gross unrealized losses	1,997	2,554
Fair value	14,144	14,399
Foreign government
Investments summary
Securities available-for-sale, at fair value	89,277	84,514
Securities available-for-sale
Amortized cost	88,981	84,360
Gross unrealized gains	595	558
Gross unrealized losses	299	404
Fair value	89,277	84,514
Corporate
Investments summary
Securities available-for-sale, at fair value	11,974	10,257
Debt securities held-to-maturity	1,074	1,749
Securities available-for-sale
Amortized cost	11,688	10,005
Gross unrealized gains	318	305
Gross unrealized losses	32	53
Fair value	11,974	10,257
Asset-backed securities
Investments summary
Securities available-for-sale, at fair value	10,846	11,003
Debt securities held-to-maturity	943	977
Securities available-for-sale
Amortized cost	10,871	11,053
Gross unrealized gains	39	31
Gross unrealized losses	64	81
Fair value	10,846	11,003
Other debt securities
Investments summary
Securities available-for-sale, at fair value	610	683
Securities available-for-sale
Amortized cost	595	670
Gross unrealized gains	15	13
Fair value	610	683
Total debt securities AFS
Investments summary
Securities available-for-sale, at fair value	268,159	257,019
Securities available-for-sale
Amortized cost	266,611	255,656
Gross unrealized gains	4,085	4,545
Gross unrealized losses	2,537	3,182
Fair value	268,159	257,019
Marketable equity securities AFS
Investments summary
Securities available-for-sale, at fair value	2,423	8,185
Securities available-for-sale
Amortized cost	2,542	6,722
Gross unrealized gains	48	1,658
Gross unrealized losses	167	195
Fair value	2,423	8,185
Total securities AFS
Investments summary
Securities available-for-sale, at fair value	270,582	265,204
Securities available-for-sale
Amortized cost	269,153	262,378
Gross unrealized gains	4,133	6,203
Gross unrealized losses	2,704	3,377
Fair value	$ 270,582	$ 265,204

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This element represents the aggregate carrying amount of all cost-method investments held by the Company. Generally, such investments do not have readily determinable fair values and are not required to be accounted for by the equity method. The carrying amount of such securities equates to cost, adjusted for other-than-temporary impairment. The cost method and lower-of-cost or market, an adaptation of the cost method, is generally followed for most investments in noncontrolled corporations, in some corporate joint ventures, and to a lesser extent in unconsolidated subsidiaries, particularly foreign.

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