Results of Operations and Average Assets by Segment (Detail) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014		Sep. 30, 2015		Sep. 30, 2014		Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net interest income	$ 901		$ 903		$ 2,636		$ 2,697
Provision for loan and lease losses	156		71		305		216
Net interest income (loss) after provision for loan and lease losses	745		832		2,331		2,481
Total noninterest income	713		520		1,900		1,820
Total noninterest expense	943		888		2,814		2,792
Income (Loss) Before Income Taxes	515		464		1,417		1,509
Applicable income tax benefit	134		124		367		411
Net income (loss)	381		340		1,050		1,098
Less: Net income attributable to noncontrolling interests					(6)		2
Net income attributable to Bancorp	381		340		1,056		1,096
Dividends on preferred stock	15		12		52		44
Net income available to common shareholders	366		328		1,004		1,052
Total goodwill	2,416		2,416		2,416		2,416		$ 2,416	$ 2,416
Total Assets	141,918		134,188		141,918		134,188		$ 138,706
Commercial Banking
Segment Reporting Information [Line Items]
Net interest income	413		411		1,207		1,212
Provision for loan and lease losses	138		47		208		184
Net interest income (loss) after provision for loan and lease losses	275		364		999		1,028
Total noninterest income	228	[1]	218		630	[2]	642
Total noninterest expense	342		323		1,056		986
Income (Loss) Before Income Taxes	161		259		573		684
Applicable income tax benefit	8		47		54		104
Net income (loss)	153		212		519		580
Net income attributable to Bancorp	153		212		519		580
Net income available to common shareholders	153		212		519		580
Total goodwill	613		613		613		613
Total Assets	59,448		55,906		59,448		55,906
Branch Banking
Segment Reporting Information [Line Items]
Net interest income	395		396		1,148		1,171
Provision for loan and lease losses	39		50		122		142
Net interest income (loss) after provision for loan and lease losses	356		346		1,026		1,029
Total noninterest income	197	[3]	194		468	[4]	538	[5]
Total noninterest expense	396		392		1,183		1,168
Income (Loss) Before Income Taxes	157		148		311		399
Applicable income tax benefit	55		52		110		141
Net income (loss)	102		96		201		258
Net income attributable to Bancorp	102		96		201		258
Net income available to common shareholders	102		96		201		258
Total goodwill	1,655		1,655		1,655		1,655
Total Assets	52,163		50,125		52,163		50,125
Consumer Lending
Segment Reporting Information [Line Items]
Net interest income	62		64		187		193
Provision for loan and lease losses	11		17		33		55
Net interest income (loss) after provision for loan and lease losses	51		47		154		138
Total noninterest income	76		71		327		280
Total noninterest expense	106		114		322		446
Income (Loss) Before Income Taxes	21		4		159		(28)
Applicable income tax benefit	8		1		57		(10)
Net income (loss)	13		3		102		(18)
Net income attributable to Bancorp	13		3		102		(18)
Net income available to common shareholders	13		3		102		(18)
Total Assets	22,805		22,644		22,805		22,644
Investment Advisors
Segment Reporting Information [Line Items]
Net interest income	33		30		91		90
Provision for loan and lease losses			1		3		3
Net interest income (loss) after provision for loan and lease losses	33		29		88		87
Total noninterest income	102		102		315		308
Total noninterest expense	112		111		342		333
Income (Loss) Before Income Taxes	23		20		61		62
Applicable income tax benefit	8		7		21		22
Net income (loss)	15		13		40		40
Net income attributable to Bancorp	15		13		40		40
Net income available to common shareholders	15		13		40		40
Total goodwill	148		148		148		148
Total Assets	8,964		9,856		8,964		9,856
General Corporate and Other
Segment Reporting Information [Line Items]
Net interest income	(2)		2		3		31
Provision for loan and lease losses	(32)		(44)		(61)		(168)
Net interest income (loss) after provision for loan and lease losses	30		46		64		199
Total noninterest income	148		(27)		274		162
Total noninterest expense	25		(14)		25		(31)
Income (Loss) Before Income Taxes	153		33		313		392
Applicable income tax benefit	55		17		125		154
Net income (loss)	98		16		188		238
Less: Net income attributable to noncontrolling interests					(6)		2
Net income attributable to Bancorp	98		16		194		236
Dividends on preferred stock	15		12		52		44
Net income available to common shareholders	83		4		142		192
Total Assets	(1,462)		(4,343)		(1,462)		(4,343)
Intersegment Elimination
Segment Reporting Information [Line Items]
Total noninterest income	(38)	[6]	(38)	[7]	(114)	[8]	(110)	[9]
Total noninterest expense	$ (38)		$ (38)		$ (114)		$ (110)

[1] Includes an impairment charge of $2 for operating lease equipment. For more information refer to Note 8 and Note 22.

[2] Includes an impairment charge of $36 for operating lease equipment. For more information refer to Note 8 and Note 22

[3] Includes an impairment charge of $2 for branches and land. For more information refer to Note 7 and Note 22.

[4] Includes an impairment charge of $104 for branches and land. For more information refer to Note 7 and Note 22.

[5] Includes an impairment charge of $18 for branches and land. For more information refer to Note 7 and Note 22.

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

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

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

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