Results of Operations and Average Assets by Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011		Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Net interest income	$ 903		$ 898		$ 2,696		$ 2,641
Provision for loan and lease losses	65		87		227		368
Net interest income (loss) after provision for loan and lease losses	838		811		2,469		2,273
Noninterest income:
Mortgage banking net revenue	200		178		588		442
Service charges on deposits	128		134		387		384
Investment advisory revenue	92		92		281		285
Corporate banking revenue	101		87		299		268
Card and processing revenue	65		78		187		248
Other noninterest income	78		64		359		226
Securities gains, net	2		26		13		40
Securities gains, net - non-qualifying hedges on mortgage servicing rights	5		6		5		12
Total noninterest income	671		665		2,119		1,905
Noninterest expense:
Salaries, wages and incentives	399		369		1,191		1,085
Employee benefits	79		70		274		246
Net occupancy expense	76		75		227		226
Technology and communications	49		48		144		140
Card and processing expense	30		34		90		92
Equipment expense	28		28		82		85
Other noninterest expense	345		322		910		891
Total noninterest expense	1,006		946		2,918		2,765
Income (loss) before income taxes	503		530		1,670		1,413
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	139		149		491		429
Net income (loss)	364		381		1,179		984
Less: Net income attributable to noncontrolling interests	(1)				(1)		(1)
Net income attributable to Bancorp	363		381		1,178		983
Dividends on preferred stock	9		8		26		194
Net income available to common shareholders	354		373		1,152		789
Total goodwill	2,417		2,417		2,417		2,417		2,417	2,417
Total Assets	117,483		114,905		117,483		114,905		116,967
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	354		341		1,049		1,003
Provision for loan and lease losses	45		104		181		402
Net interest income (loss) after provision for loan and lease losses	309		237		868		601
Noninterest income:
Service charges on deposits	57		53		166		154
Investment advisory revenue	1		3		5		9
Corporate banking revenue	96		82		286		254
Card and processing revenue	11		10		35		29
Other noninterest income	18		11		45		51
Total noninterest income	183		159		537		497
Noninterest expense:
Salaries, wages and incentives	53		51		166		147
Employee benefits	7		9		32		30
Net occupancy expense	5		5		16		15
Technology and communications	3		2		7		8
Card and processing expense	1		1		3		4
Equipment expense	1		1		2		2
Other noninterest expense	201		189		603		597
Total noninterest expense	271		258		829		803
Income (loss) before income taxes	221		138		576		295
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	39		8		90		(2)
Net income (loss)	182		130		486		297
Net income attributable to Bancorp	182		130		486		297
Net income available to common shareholders	182		130		486		297
Total goodwill	613		613		613		613		613	613
Total Assets	47,495		44,615		47,495		44,615
Branch Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	344		359		1,021		1,057
Provision for loan and lease losses	71		87		226		300
Net interest income (loss) after provision for loan and lease losses	273		272		795		757
Noninterest income:
Mortgage banking net revenue	3		3		10		6
Service charges on deposits	70		81		219		228
Investment advisory revenue	33		30		96		89
Corporate banking revenue	4		4		11		11
Card and processing revenue	72		78		202		241
Other noninterest income	21		19		60		57
Total noninterest income	203		215		598		632
Noninterest expense:
Salaries, wages and incentives	111		114		337		343
Employee benefits	31		31		98		100
Net occupancy expense	47		47		140		138
Technology and communications	1		1		3		4
Card and processing expense	29		33		86		88
Equipment expense	14		13		40		38
Other noninterest expense	172		160		496		478
Total noninterest expense	405		399		1,200		1,189
Income (loss) before income taxes	71		88		193		200
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	25		31		68		69
Net income (loss)	46		57		125		131
Net income attributable to Bancorp	46		57		125		131
Net income available to common shareholders	46		57		125		131
Total goodwill	1,656		1,656		1,656		1,656		1,656	1,656
Total Assets	48,003		46,727		48,003		46,727
Consumer Lending [Member]
Segment Reporting Information [Line Items]
Net interest income	77		85		234		256
Provision for loan and lease losses	38		55		140		205
Net interest income (loss) after provision for loan and lease losses	39		30		94		51
Noninterest income:
Mortgage banking net revenue	197		175		577		435
Other noninterest income	10		10		30		26
Securities gains, net - non-qualifying hedges on mortgage servicing rights	5		6		5		12
Total noninterest income	212		191		612		473
Noninterest expense:
Salaries, wages and incentives	49		37		139		102
Employee benefits	9		8		30		26
Net occupancy expense	2		2		6		6
Technology and communications					1		1
Equipment expense					1		1
Other noninterest expense	107		111		319		318
Total noninterest expense	167		158		496		454
Income (loss) before income taxes	84		63		210		70
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	30		22		74		24
Net income (loss)	54		41		136		46
Net income attributable to Bancorp	54		41		136		46
Net income available to common shareholders	54		41		136		46
Total Assets	23,640		23,213		23,640		23,213
Investment Advisors [Member]
Segment Reporting Information [Line Items]
Net interest income	30		29		87		85
Provision for loan and lease losses	3		16		9		25
Net interest income (loss) after provision for loan and lease losses	27		13		78		60
Noninterest income:
Mortgage banking net revenue					1		1
Service charges on deposits	1		1		2		3
Investment advisory revenue	90		89		275		275
Corporate banking revenue	1		1		2		2
Card and processing revenue	1		1		3		3
Other noninterest income	14				19
Total noninterest income	107		92		302		284
Noninterest expense:
Salaries, wages and incentives	33		34		103		103
Employee benefits	6		6		20		21
Net occupancy expense	3		3		8		8
Technology and communications							1
Equipment expense					1		1
Other noninterest expense	67		62		199		182
Total noninterest expense	109		105		331		316
Income (loss) before income taxes	25				49		28
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	9				17		10
Net income (loss)	16				32		18
Net income attributable to Bancorp	16				32		18
Net income available to common shareholders	16				32		18
Total goodwill	148		148		148		148		148	148
Total Assets	8,024		7,358		8,024		7,358
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Net interest income	98		84		305		240
Provision for loan and lease losses	(92)		(175)		(329)		(564)
Net interest income (loss) after provision for loan and lease losses	190		259		634		804
Noninterest income:
Service charges on deposits			(1)				(1)
Corporate banking revenue							1
Card and processing revenue	(19)		(11)		(53)		(25)
Other noninterest income	15		24		205		92
Securities gains, net	2		26		13		40
Total noninterest income	(2)		38		165		107
Noninterest expense:
Salaries, wages and incentives	153		133		446		390
Employee benefits	26		16		94		69
Net occupancy expense	19		18		57		59
Technology and communications	45		45		133		126
Card and processing expense					1
Equipment expense	13		14		38		43
Other noninterest expense	(170)		(170)		(612)		(596)
Total noninterest expense	86		56		157		91
Income (loss) before income taxes	102		241		642		820
Income Tax Expense Benefit Including Fully Taxable Equivalent Adjustment	36		88		242		328
Net income (loss)	66		153		400		492
Less: Net income attributable to noncontrolling interests	(1)				(1)		(1)
Net income attributable to Bancorp	65		153		399		491
Dividends on preferred stock	9		8		26		194
Net income available to common shareholders	56		145		373		297
Total Assets	(9,679)		(7,008)		(9,679)		(7,008)
Business Intersegment, Eliminations
Noninterest income:
Investment advisory revenue	(32)	[1]	(30)	[1]	(95)	[1]	(88)	[1]
Total noninterest income	(32)	[1]	(30)	[1]	(95)	[1]	(88)	[1]
Noninterest expense:
Other noninterest expense	(32)	[1]	(30)	[1]	(95)	[1]	(88)	[1]
Total noninterest expense	$ (32)	[1]	$ (30)	[1]	$ (95)	[1]	$ (88)	[1]

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