Business Segment Reporting (Detail) (USD $)	3 Months Ended		12 Months Ended
	Dec. 31, 2011		Dec. 31, 2011	Dec. 31, 2010		Dec. 31, 2009		Sep. 30, 2010
Business Acquisition, Purchase Price Allocation, Assets Acquired								$ 17,000,000,000
Average total assets	172,440,000,000			172,375,000,000		175,442,000,000
Average total liabilities	151,744,000,000			149,541,000,000		153,156,000,000
Average total equity	20,696,000,000			22,834,000,000		22,286,000,000
Net, interest income	5,065,000,000		5,065,000,000	4,854,000,000		4,466,000,000
FTE adjustment	114,000,000			116,000,000		123,000,000
Net interest income (FTE)	5,179,000,000	[1]		4,970,000,000	[1]	4,589,000,000	[1]
Provision for credit losses	1,513,000,000	[2]		2,651,000,000	[2]	4,064,000,000	[2]
Net interest income/(loss) after provision for credit losses	3,666,000,000			2,319,000,000		525,000,000
Noninterest income	3,421,000,000		3,421,000,000	3,729,000,000		3,710,000,000
Noninterest expense	6,234,000,000		6,234,000,000	5,911,000,000		6,562,000,000
Income/(loss) before provision/(benefit) for income taxes	853,000,000			137,000,000		(2,327,000,000)
Provision/(benefit) for income taxes	193,000,000	[3]		(69,000,000)	[3]	(775,000,000)	[3]
Net income/(loss) including income attributable to noncontrolling interest	660,000,000		660,000,000	206,000,000		(1,552,000,000)
Net income attributable to noncontrolling interest	13,000,000		13,000,000	17,000,000		12,000,000
Net income/(loss)	647,000,000		647,000,000	189,000,000		(1,564,000,000)
Retail Banking
Average total assets	41,071,000,000			39,204,000,000		39,249,000,000
Average total liabilities	77,458,000,000			75,574,000,000		73,128,000,000
Average total equity	0			0		0
Net, interest income	2,543,000,000			2,500,000,000		2,295,000,000
FTE adjustment	0			0		0
Net interest income (FTE)	2,543,000,000	[1]		2,500,000,000	[1]	2,295,000,000	[1]
Provision for credit losses	784,000,000	[2]		992,000,000	[2]	1,236,000,000	[2]
Net interest income/(loss) after provision for credit losses	1,759,000,000			1,508,000,000		1,059,000,000
Noninterest income	1,064,000,000			1,129,000,000		1,152,000,000
Noninterest expense	2,521,000,000			2,526,000,000		2,536,000,000
Income/(loss) before provision/(benefit) for income taxes	302,000,000			111,000,000		(325,000,000)
Provision/(benefit) for income taxes	109,000,000	[3]		38,000,000	[3]	(122,000,000)	[3]
Net income/(loss) including income attributable to noncontrolling interest	193,000,000			73,000,000		(203,000,000)
Net income attributable to noncontrolling interest	0			0		0
Net income/(loss)	193,000,000			73,000,000		(203,000,000)
Diversified Commercial Banking
Average total assets	25,237,000,000			24,862,000,000		26,766,000,000
Average total liabilities	21,740,000,000			20,815,000,000		19,939,000,000
Average total equity	0			0		0
Net, interest income	622,000,000			552,000,000		472,000,000
FTE adjustment	103,000,000			105,000,000		107,000,000
Net interest income (FTE)	725,000,000	[1]		657,000,000	[1]	579,000,000	[1]
Provision for credit losses	92,000,000	[2]		127,000,000	[2]	112,000,000	[2]
Net interest income/(loss) after provision for credit losses	633,000,000			530,000,000		467,000,000
Noninterest income	251,000,000			235,000,000		247,000,000
Noninterest expense	460,000,000			448,000,000		467,000,000
Income/(loss) before provision/(benefit) for income taxes	424,000,000			317,000,000		247,000,000
Provision/(benefit) for income taxes	155,000,000	[3]		114,000,000	[3]	90,000,000	[3]
Net income/(loss) including income attributable to noncontrolling interest	269,000,000			203,000,000		157,000,000
Net income attributable to noncontrolling interest	0			0		0
Net income/(loss)	269,000,000			203,000,000		157,000,000
Commercial Real Estate
Average total assets	7,961,000,000			10,743,000,000		13,631,000,000
Average total liabilities	1,568,000,000			1,662,000,000		2,398,000,000
Average total equity	0			0		0
Net, interest income	139,000,000			162,000,000		178,000,000
FTE adjustment	1,000,000			0		0
Net interest income (FTE)	140,000,000	[1]		162,000,000	[1]	178,000,000	[1]
Provision for credit losses	422,000,000	[2]		442,000,000	[2]	435,000,000	[2]
Net interest income/(loss) after provision for credit losses	(282,000,000)			(280,000,000)		(257,000,000)
Noninterest income	100,000,000			88,000,000		94,000,000
Noninterest expense	448,000,000			469,000,000		730,000,000
Income/(loss) before provision/(benefit) for income taxes	(630,000,000)			(661,000,000)		(893,000,000)
Provision/(benefit) for income taxes	(320,000,000)	[3]		(332,000,000)	[3]	(302,000,000)	[3]
Net income/(loss) including income attributable to noncontrolling interest	(310,000,000)			(329,000,000)		(591,000,000)
Net income attributable to noncontrolling interest	0			0		0
Net income/(loss)	(310,000,000)			(329,000,000)		(591,000,000)
Corporate and Investment Banking
Average total assets	22,959,000,000			20,039,000,000		21,416,000,000
Average total liabilities	17,879,000,000			16,146,000,000		12,400,000,000
Average total equity	0			0		0
Net, interest income	498,000,000			381,000,000		304,000,000
FTE adjustment	3,000,000			1,000,000		2,000,000
Net interest income (FTE)	501,000,000	[1]		382,000,000	[1]	306,000,000	[1]
Provision for credit losses	(10,000,000)	[2]		50,000,000	[2]	248,000,000	[2]
Net interest income/(loss) after provision for credit losses	511,000,000			332,000,000		58,000,000
Noninterest income	636,000,000			672,000,000		616,000,000
Noninterest expense	587,000,000			498,000,000		486,000,000
Income/(loss) before provision/(benefit) for income taxes	560,000,000			506,000,000		188,000,000
Provision/(benefit) for income taxes	205,000,000	[3]		186,000,000	[3]	71,000,000	[3]
Net income/(loss) including income attributable to noncontrolling interest	355,000,000			320,000,000		117,000,000
Net income attributable to noncontrolling interest	0			0		0
Net income/(loss)	355,000,000			320,000,000		117,000,000
Mortgage
Average total assets	33,719,000,000			34,791,000,000		37,295,000,000
Average total liabilities	3,838,000,000			4,031,000,000		3,944,000,000
Average total equity	0			0		0
Net, interest income	492,000,000			458,000,000		500,000,000
FTE adjustment	0			0		0
Net interest income (FTE)	492,000,000	[1]		458,000,000	[1]	500,000,000	[1]
Provision for credit losses	693,000,000	[2]		1,183,000,000	[2]	1,125,000,000	[2]
Net interest income/(loss) after provision for credit losses	(201,000,000)			(725,000,000)		(625,000,000)
Noninterest income	241,000,000			521,000,000		687,000,000
Noninterest expense	1,172,000,000			1,065,000,000		1,389,000,000
Income/(loss) before provision/(benefit) for income taxes	(1,132,000,000)			(1,269,000,000)		(1,327,000,000)
Provision/(benefit) for income taxes	(439,000,000)	[3]		(483,000,000)	[3]	(355,000,000)	[3]
Net income/(loss) including income attributable to noncontrolling interest	(693,000,000)			(786,000,000)		(972,000,000)
Net income attributable to noncontrolling interest	0			1,000,000		3,000,000
Net income/(loss)	(693,000,000)			(787,000,000)		(975,000,000)
Wealth and Investment Management
Average total assets	8,616,000,000			9,085,000,000		9,133,000,000
Average total liabilities	13,036,000,000			11,935,000,000		11,560,000,000
Average total equity	0			0		0
Net, interest income	417,000,000			385,000,000		345,000,000
FTE adjustment	0			0		0
Net interest income (FTE)	417,000,000	[1]		385,000,000	[1]	345,000,000	[1]
Provision for credit losses	60,000,000	[2]		61,000,000	[2]	79,000,000	[2]
Net interest income/(loss) after provision for credit losses	357,000,000			324,000,000		266,000,000
Noninterest income	822,000,000			821,000,000		754,000,000
Noninterest expense	922,000,000			919,000,000		858,000,000
Income/(loss) before provision/(benefit) for income taxes	257,000,000			226,000,000		162,000,000
Provision/(benefit) for income taxes	94,000,000	[3]		81,000,000	[3]	62,000,000	[3]
Net income/(loss) including income attributable to noncontrolling interest	163,000,000			145,000,000		100,000,000
Net income attributable to noncontrolling interest	3,000,000			7,000,000		0
Net income/(loss)	160,000,000			138,000,000		100,000,000
Corporate Other and Treasury
Average total assets	31,576,000,000			32,827,000,000		26,713,000,000
Average total liabilities	16,432,000,000			19,483,000,000		29,641,000,000
Average total equity	0			0		0
Net, interest income	514,000,000			474,000,000		429,000,000
FTE adjustment	6,000,000			10,000,000		14,000,000
Net interest income (FTE)	520,000,000	[1]		484,000,000	[1]	443,000,000	[1]
Provision for credit losses	(1,000,000)	[2]		0	[2]	2,000,000	[2]
Net interest income/(loss) after provision for credit losses	521,000,000			484,000,000		441,000,000
Noninterest income	333,000,000			295,000,000		192,000,000
Noninterest expense	153,000,000			19,000,000		128,000,000
Income/(loss) before provision/(benefit) for income taxes	701,000,000			760,000,000		505,000,000
Provision/(benefit) for income taxes	245,000,000	[3]		262,000,000	[3]	115,000,000	[3]
Net income/(loss) including income attributable to noncontrolling interest	456,000,000			498,000,000		390,000,000
Net income attributable to noncontrolling interest	9,000,000			9,000,000		9,000,000
Net income/(loss)	447,000,000			489,000,000		381,000,000
Reconciling Items
Average total assets	1,301,000,000			824,000,000		1,239,000,000
Average total liabilities	(207,000,000)			(105,000,000)		146,000,000
Average total equity	20,696,000,000			22,834,000,000		22,286,000,000
Net, interest income	(160,000,000)			(58,000,000)		(57,000,000)
FTE adjustment	1,000,000			0		0
Net interest income (FTE)	(159,000,000)	[1]		(58,000,000)	[1]	(57,000,000)	[1]
Provision for credit losses	(527,000,000)	[2]		(204,000,000)	[2]	827,000,000	[2]
Net interest income/(loss) after provision for credit losses	368,000,000			146,000,000		(884,000,000)
Noninterest income	(26,000,000)			(32,000,000)		(32,000,000)
Noninterest expense	(29,000,000)			(33,000,000)		(32,000,000)
Income/(loss) before provision/(benefit) for income taxes	371,000,000			147,000,000		(884,000,000)
Provision/(benefit) for income taxes	144,000,000	[3]		65,000,000	[3]	(334,000,000)	[3]
Net income/(loss) including income attributable to noncontrolling interest	227,000,000			82,000,000		(550,000,000)
Net income attributable to noncontrolling interest	1,000,000			0		0
Net income/(loss)	$ 226,000,000			$ 82,000,000		$ (550,000,000)

[1] Net interest income is FTE and is presented on a matched maturity funds transfer price basis for the segments.

[2] Provision for credit losses represents net charge-offs for the segments.

[3] Includes regular income tax provision/(benefit) and taxable-equivalent income adjustment reversal.