Credit Quality (Summarizes the Bancorp's Recorded Investment in Impaired Loans and Related Allowance by Class) (Parenthetical) (Detail) $ in Millions	3 Months Ended				9 Months Ended				12 Months Ended
	Sep. 30, 2016 USD ($)		Sep. 30, 2015 USD ($)	[5],[6]	Sep. 30, 2016 USD ($)		Sep. 30, 2015		Dec. 31, 2015 USD ($)
Financing Receivable, Impaired
Unpaid principal balance	$ 2,102				$ 2,102				$ 2,029
Recorded investment	1,914	[1]			1,914	[1]			1,842	[2]
Allowance	$ 189				$ 189				220
Number of contracts	2,687	[3],[4]	3,551		8,366	[3],[4]	11,227	[5],[6]
Commercial Portfolio Segment | Commercial and Industrial Loans
Financing Receivable, Impaired
Allowance	$ 74				$ 74				84
Number of contracts	12	[3],[4]	15		56	[3],[4]	63	[5],[6]
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied
Financing Receivable, Impaired
Allowance	$ 2	[7]			$ 2	[7]			5	[8]
Number of contracts	1	[3],[4]	1		11	[3],[4]	14	[5],[6]
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied | Variable Interest Entity, Primary Beneficiary
Financing Receivable, Impaired
Unpaid principal balance	$ 27				$ 27				27
Recorded investment	27				27				27
Allowance	18				$ 18				$ 15
Number of contracts					5		5		5
Commercial Portfolio Segment | Commercial Mortgage Loans, Nonowner-Occupied
Financing Receivable, Impaired
Allowance	$ 2				$ 2				$ 12
Number of contracts	0	[3],[4]	0		4	[3],[4]	11	[5],[6]
Commercial Portfolio Segment | Troubled Debt Restructuring On Accrual Status
Financing Receivable, Impaired
Recorded investment	$ 408				$ 408				491
Commercial Portfolio Segment | Troubled Debt Restructuring On Nonaccrual Status
Financing Receivable, Impaired
Recorded investment	194				194				203
Residential Mortgage Loans
Financing Receivable, Impaired
Allowance	$ 68				$ 68				67
Number of contracts	240	[3],[4]	301		745	[3],[4]	855	[5],[6]
Residential Mortgage Loans | Troubled Debt Restructuring On Accrual Status
Financing Receivable, Impaired
Recorded investment	$ 638				$ 638				607
Residential Mortgage Loans | Troubled Debt Restructuring On Nonaccrual Status
Financing Receivable, Impaired
Recorded investment	13				13				23
Consumer Portfolio Segment | Troubled Debt Restructuring On Accrual Status
Financing Receivable, Impaired
Recorded investment	334				334				327
Consumer Portfolio Segment | Troubled Debt Restructuring On Nonaccrual Status
Financing Receivable, Impaired
Recorded investment	$ 50				$ 50				$ 52

[1] Includes $ 408 , $ 638 and $ 334 , respectively, of commercial, residential mortgage and consumer portfolio TDRs on accrual status and $ 194 , $ 13 an d $ 50 , respectively , of commercial , residential mortgage and consumer portfolio TDRs on nonaccrual status at September 30, 2016 .

[2] Includes $ 491 , $ 607 and $ 327 , respectively, of commercial, residential mortgage and consumer portfolio TDR s on accrual status and $ 203 , $ 23 and $ 52 , respectively , of commercial, residential mortgage and consumer portfolio TDRs on nonaccrual status at December 31, 2015 .

[3] Excludes all loans and leases held for sale and loans acquired with deteriorated credit quality which were accounted for within a pool .

[4] Represents number of loans post-modification and excludes loans previously modified in a TDR .

[5] Excludes all loans and leases held for sale and loans acquired with deteriorated credit quality which were accounted for within a pool .

[6] Represents number of loans post-modification and excludes loans previously modified in a TDR .

[7] Excludes five restructured loans at September 30, 2016 associated with a consolidated VIE in which the Bancorp has no continuing credit risk due to the risk being assumed by a third party, with an unpaid principal balance of $ 27 , a recorded investment of $ 27 and an ALLL of $ 18 .

[8] Excludes five restructured loans at December 31, 2015 associated with a consolidated VIE in which the Bancorp has no continuing credit risk due to the risk being assumed by a third party, with an unpaid principal balance of $ 27 , a recorded investment of $ 27 and an ALLL of $ 15 .