Results of Operations and Average Assets by Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011		Dec. 31, 2011
Segment Reporting Information [Line Items]
Net interest income	$ 895		$ 864		$ 1,793		$ 1,743
Provision for loan and lease losses	71		113		162		281
Net interest income (loss) after provision for loan and lease losses	824		751		1,631		1,462
Noninterest income:
Mortgage banking net revenue	183		162		387		264
Service charges on deposits	130		126		260		250
Investment advisory revenue	93		95		190		193
Corporate banking revenue	102		95		199		181
Card and processing revenue	64		89		122		169
Other noninterest income	103		83		279		164
Securities gains, net	3		6		11		14
Securities gains, net - non-qualifying hedges on mortgage servicing rights							5
Total noninterest income	678		656		1,448		1,240
Noninterest expense:
Salaries, wages and incentives	393		365		792		716
Employee benefits	84		79		195		176
Net occupancy expense	74		75		151		152
Technology and communications	48		48		95		93
Card and processing expense	30		29		60		58
Equipment expense	27		28		55		57
Other noninterest expense	281		277		563		567
Total noninterest expense	937		901		1,911		1,819
Income (loss) before income taxes	565		506		1,168		883
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	180		169		352		281
Net income (loss)	385		337		816		602
Less: Net income attributable to noncontrolling interest					(1)
Net income (loss)	385		337		815		602
Dividends on preferred stock	9		9		18		185
Net income available to common shareholders	376		328		797		417
Total goodwill	2,417		2,417		2,417		2,417		2,417
Total Assets	117,543		110,805		117,543		110,805		116,967
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	348		334		696		662
Provision for loan and lease losses	61		147		137		299
Net interest income (loss) after provision for loan and lease losses	287		187		559		363
Noninterest income:
Service charges on deposits	54		52		109		101
Investment advisory revenue	2		3		4		6
Corporate banking revenue	97		90		190		172
Card and processing revenue	12		10		23		19
Other noninterest income	12		8		28		40
Total noninterest income	177		163		354		338
Noninterest expense:
Salaries, wages and incentives	56		50		113		95
Employee benefits	9		10		24		22
Net occupancy expense	5		5		11		10
Technology and communications	2		3		4		6
Card and processing expense	1		1		2		2
Equipment expense			1		1		1
Other noninterest expense	196		206		402		408
Total noninterest expense	269		276		557		544
Income (loss) before income taxes	195		74		356		157
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	32		(14)		51		(13)
Net income (loss)	163		88		305		170
Net income (loss)	163		88		305		170
Net income available to common shareholders	163		88		305		170
Total goodwill	613		613		613		613
Total Assets	46,691		43,571		46,691		43,571
Branch Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	342		359		677		698
Provision for loan and lease losses	69		98		155		214
Net interest income (loss) after provision for loan and lease losses	273		261		522		484
Noninterest income:
Mortgage banking net revenue	4		2		6		4
Service charges on deposits	75		73		149		147
Investment advisory revenue	32		29		64		58
Corporate banking revenue	4		4		7		7
Card and processing revenue	70		86		130		163
Other noninterest income	20		19		39		38
Total noninterest income	205		213		395		417
Noninterest expense:
Salaries, wages and incentives	113		115		226		229
Employee benefits	30		33		67		68
Net occupancy expense	47		46		93		92
Technology and communications	1		1		2		2
Card and processing expense	29		28		57		55
Equipment expense	13		13		26		25
Other noninterest expense	168		155		324		319
Total noninterest expense	401		391		795		790
Income (loss) before income taxes	77		83		122		111
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	27		29		43		38
Net income (loss)	50		54		79		73
Net income (loss)	50		54		79		73
Net income available to common shareholders	50		54		79		73
Total goodwill	1,656		1,656		1,656		1,656
Total Assets	48,156		46,961		48,156		46,961
Consumer Lending [Member]
Segment Reporting Information [Line Items]
Net interest income	77		81		157		171
Provision for loan and lease losses	49		55		103		149
Net interest income (loss) after provision for loan and lease losses	28		26		54		22
Noninterest income:
Mortgage banking net revenue	179		160		380		259
Other noninterest income	10		7		20		17
Securities gains, net - non-qualifying hedges on mortgage servicing rights							5
Total noninterest income	189		167		400		281
Noninterest expense:
Salaries, wages and incentives	47		31		91		64
Employee benefits	9		8		21		19
Net occupancy expense	2		2		4		4
Technology and communications			1				1
Other noninterest expense	108		105		213		208
Total noninterest expense	166		147		329		296
Income (loss) before income taxes	51		46		125		7
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	18		16		44		2
Net income (loss)	33		30		81		5
Net income (loss)	33		30		81		5
Net income available to common shareholders	33		30		81		5
Total Assets	23,538		22,044		23,538		22,044
Investment Advisors [Member]
Segment Reporting Information [Line Items]
Net interest income	29		28		57		56
Provision for loan and lease losses	2		4		6		9
Net interest income (loss) after provision for loan and lease losses	27		24		51		47
Noninterest income:
Mortgage banking net revenue					1		1
Service charges on deposits	1		1		2		2
Investment advisory revenue	91		92		185		187
Corporate banking revenue	1		1		2		1
Card and processing revenue	1		1		2		2
Other noninterest income	4				4
Total noninterest income	98		95		196		193
Noninterest expense:
Salaries, wages and incentives	35		36		69		70
Employee benefits	6		6		15		15
Net occupancy expense	3		3		6		5
Technology and communications							1
Other noninterest expense	68		59		132		121
Total noninterest expense	112		104		222		212
Income (loss) before income taxes	13		15		25		28
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	5		5		9		10
Net income (loss)	8		10		16		18
Net income (loss)	8		10		16		18
Net income available to common shareholders	8		10		16		18
Total goodwill	148		148		148		148
Total Assets	7,721		6,833		7,721		6,833
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Net interest income	99		62		206		156
Provision for loan and lease losses	(110)		(191)		(239)		(390)
Net interest income (loss) after provision for loan and lease losses	209		253		445		546
Noninterest income:
Investment advisory revenue					1
Corporate banking revenue							1
Card and processing revenue	(19)		(8)		(33)		(15)
Other noninterest income	57		49		188		69
Securities gains, net	3		6		11		14
Total noninterest income	41		47		167		69
Noninterest expense:
Salaries, wages and incentives	142		133		293		258
Employee benefits	30		22		68		52
Net occupancy expense	17		19		37		41
Technology and communications	45		43		89		83
Card and processing expense					1		1
Equipment expense	14		14		28		31
Other noninterest expense	(227)		(219)		(444)		(431)
Total noninterest expense	21		12		72		35
Income (loss) before income taxes	229		288		540		580
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	98		133		205		244
Net income (loss)	131		155		335		336
Less: Net income attributable to noncontrolling interest					(1)
Net income (loss)	131		155		334		336
Dividends on preferred stock	9		9		18		185
Net income available to common shareholders	122		146		316		151
Total Assets	(8,563)		(8,604)		(8,563)		(8,604)
Business Intersegment, Eliminations
Noninterest income:
Investment advisory revenue	(32)	[1]	(29)	[1]	(64)	[1]	(58)	[1]
Total noninterest income	(32)	[1]	(29)	[1]	(64)	[1]	(58)	[1]
Noninterest expense:
Other noninterest expense	(32)	[1]	(29)	[1]	(64)	[1]	(58)	[1]
Total noninterest expense	$ (32)	[1]	$ (29)	[1]	$ (64)	[1]	$ (58)	[1]

[1] (a)     Revenue sharing agreements between Investment Advisors and Branch Banking are eliminated in the Condensed Consolidated Statements of Income.