INVESTMENTS (Details) (USD $)	3 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Investments summary
Securities available-for-sale, at fair value	$ 279,586,000,000	$ 265,204,000,000
Debt securities held-to-maturity	11,349,000,000	11,483,000,000
Non-marketable equity securities carried at fair value	6,747,000,000	8,836,000,000
Non-marketable equity securities carried at cost	8,244,000,000	7,890,000,000
Total investments	305,926,000,000	293,413,000,000
Decrease in non-marketable equity securities carried at fair value	1,300,000,000
Securities available-for-sale
Fair value	279,586,000,000	265,204,000,000
Mortgage-backed securities
Investments summary
Securities available-for-sale, at fair value	53,381,000,000	51,025,000,000
Debt securities held-to-maturity	5,667,000,000	7,430,000,000
Securities available-for-sale
Amortized cost	51,819,000,000	49,649,000,000
Gross unrealized gains	1,634,000,000	1,464,000,000
Gross unrealized losses	72,000,000	88,000,000
Fair value	53,381,000,000	51,025,000,000
U.S. government-sponsored agency guaranteed
Investments summary
Securities available-for-sale, at fair value	45,933,000,000	45,781,000,000
Securities available-for-sale
Amortized cost	44,415,000,000	44,394,000,000
Gross unrealized gains	1,577,000,000	1,438,000,000
Gross unrealized losses	59,000,000	51,000,000
Fair value	45,933,000,000	45,781,000,000
Prime
Investments summary
Securities available-for-sale, at fair value	106,000,000	113,000,000
Debt securities held-to-maturity	265,000,000	287,000,000
Securities available-for-sale
Amortized cost	107,000,000	118,000,000
Gross unrealized gains	2,000,000	1,000,000
Gross unrealized losses	3,000,000	6,000,000
Fair value	106,000,000	113,000,000
Alt-A
Investments summary
Securities available-for-sale, at fair value	17,000,000	1,000,000
Debt securities held-to-maturity	2,394,000,000	3,328,000,000
Securities available-for-sale
Amortized cost	17,000,000	1,000,000
Fair value	17,000,000	1,000,000
Subprime
Investments summary
Securities available-for-sale, at fair value	6,000,000
Debt securities held-to-maturity	207,000,000	336,000,000
Securities available-for-sale
Amortized cost	6,000,000
Fair value	6,000,000
Non-U.S. residential
Investments summary
Securities available-for-sale, at fair value	6,823,000,000	4,658,000,000
Debt securities held-to-maturity	2,330,000,000	2,967,000,000
Securities available-for-sale
Amortized cost	6,788,000,000	4,671,000,000
Gross unrealized gains	39,000,000	9,000,000
Gross unrealized losses	4,000,000	22,000,000
Fair value	6,823,000,000	4,658,000,000
Commercial
Investments summary
Securities available-for-sale, at fair value	496,000,000	472,000,000
Debt securities held-to-maturity	471,000,000	512,000,000
Securities available-for-sale
Amortized cost	486,000,000	465,000,000
Gross unrealized gains	16,000,000	16,000,000
Gross unrealized losses	6,000,000	9,000,000
Fair value	496,000,000	472,000,000
U.S. Treasury and federal agency securities
Investments summary
Securities available-for-sale, at fair value	89,472,000,000	85,138,000,000
Securities available-for-sale
Amortized cost	87,594,000,000	83,100,000,000
Gross unrealized gains	1,899,000,000	2,040,000,000
Gross unrealized losses	21,000,000	2,000,000
Fair value	89,472,000,000	85,138,000,000
U.S. Treasury
Investments summary
Securities available-for-sale, at fair value	56,983,000,000	50,229,000,000
Securities available-for-sale
Amortized cost	55,603,000,000	48,790,000,000
Gross unrealized gains	1,400,000,000	1,439,000,000
Gross unrealized losses	20,000,000
Fair value	56,983,000,000	50,229,000,000
Agency obligations
Investments summary
Securities available-for-sale, at fair value	32,489,000,000	34,909,000,000
Securities available-for-sale
Amortized cost	31,991,000,000	34,310,000,000
Gross unrealized gains	499,000,000	601,000,000
Gross unrealized losses	1,000,000	2,000,000
Fair value	32,489,000,000	34,909,000,000
State and municipal securities
Investments summary
Securities available-for-sale, at fair value	16,713,000,000	14,399,000,000
Debt securities held-to-maturity	1,247,000,000	1,327,000,000
Securities available-for-sale
Amortized cost	18,657,000,000	16,819,000,000
Gross unrealized gains	140,000,000	134,000,000
Gross unrealized losses	2,084,000,000	2,554,000,000
Fair value	16,713,000,000	14,399,000,000
Foreign government
Investments summary
Securities available-for-sale, at fair value	95,572,000,000	84,514,000,000
Debt securities held-to-maturity	2,746,000,000
Securities available-for-sale
Amortized cost	94,971,000,000	84,360,000,000
Gross unrealized gains	822,000,000	558,000,000
Gross unrealized losses	221,000,000	404,000,000
Fair value	95,572,000,000	84,514,000,000
Corporate
Investments summary
Securities available-for-sale, at fair value	9,361,000,000	10,257,000,000
Debt securities held-to-maturity	806,000,000	1,749,000,000
Securities available-for-sale
Amortized cost	9,088,000,000	10,005,000,000
Gross unrealized gains	310,000,000	305,000,000
Gross unrealized losses	37,000,000	53,000,000
Fair value	9,361,000,000	10,257,000,000
Asset-backed securities
Investments summary
Securities available-for-sale, at fair value	11,399,000,000	11,003,000,000
Debt securities held-to-maturity	883,000,000	977,000,000
Securities available-for-sale
Amortized cost	11,398,000,000	11,053,000,000
Gross unrealized gains	53,000,000	31,000,000
Gross unrealized losses	52,000,000	81,000,000
Fair value	11,399,000,000	11,003,000,000
Other debt securities
Investments summary
Securities available-for-sale, at fair value	55,000,000	683,000,000
Securities available-for-sale
Amortized cost	52,000,000	670,000,000
Gross unrealized gains	3,000,000	13,000,000
Fair value	55,000,000	683,000,000
Total debt securities AFS
Investments summary
Securities available-for-sale, at fair value	275,953,000,000	257,019,000,000
Securities available-for-sale
Amortized cost	273,579,000,000	255,656,000,000
Gross unrealized gains	4,861,000,000	4,545,000,000
Gross unrealized losses	2,487,000,000	3,182,000,000
Fair value	275,953,000,000	257,019,000,000
Marketable equity securities AFS
Investments summary
Securities available-for-sale, at fair value	3,633,000,000	8,185,000,000
Securities available-for-sale
Amortized cost	3,910,000,000	6,722,000,000
Gross unrealized gains	35,000,000	1,658,000,000
Gross unrealized losses	312,000,000	195,000,000
Fair value	3,633,000,000	8,185,000,000
Total securities AFS
Investments summary
Securities available-for-sale, at fair value	279,586,000,000	265,204,000,000
Securities available-for-sale
Amortized cost	277,489,000,000	262,378,000,000
Gross unrealized gains	4,896,000,000	6,203,000,000
Gross unrealized losses	2,799,000,000	3,377,000,000
Fair value	$ 279,586,000,000	$ 265,204,000,000