Credit Quality (Summarizes the Bancorp's Recorded Investment in Impaired Loans and Related Allowance by Class) (Parenthetical) (Detail) $ in Millions	3 Months Ended				12 Months Ended
	Mar. 31, 2017 USD ($)		Mar. 31, 2016 USD ($)		Dec. 31, 2016 USD ($)
Financing Receivable, Impaired
Unpaid principal balance	$ 1,892				$ 2,052
Recorded investment	1,770	[1]			1,901	[2]
Allowance	$ 205				212
Number of contracts	2,059	[3],[4]	3,010	[5],[6]
Commercial Portfolio Segment | Commercial and Industrial Loans
Financing Receivable, Impaired
Allowance	$ 86				94
Number of contracts	33	[3],[4]	24	[5],[6]
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied
Financing Receivable, Impaired
Allowance	$ 3	[7]			5	[8]
Number of contracts	5	[3],[4]	7	[5],[6]
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied | Variable Interest Entity, Primary Beneficiary
Financing Receivable, Impaired
Unpaid principal balance	$ 26				26
Recorded investment	26				26
Allowance	$ 18				$ 18
Number of contracts	5		5		5
Commercial Portfolio Segment | Commercial Mortgage Loans, Nonowner-Occupied
Financing Receivable, Impaired
Allowance	$ 6				$ 1
Number of contracts	1	[3],[4]	2	[5],[6]
Commercial Portfolio Segment | Troubled Debt Restructuring On Accrual Status
Financing Receivable, Impaired
Recorded investment	$ 277				322
Commercial Portfolio Segment | Troubled Debt Restructuring On Nonaccrual Status
Financing Receivable, Impaired
Recorded investment	251				192
Residential Mortgage Loans
Financing Receivable, Impaired
Allowance	$ 68				68
Number of contracts	203	[3],[4]	243	[5],[6]
Residential Mortgage Loans | Troubled Debt Restructuring On Accrual Status
Financing Receivable, Impaired
Recorded investment	$ 642				635
Residential Mortgage Loans | Troubled Debt Restructuring On Nonaccrual Status
Financing Receivable, Impaired
Recorded investment	14				17
Consumer Portfolio Segment | Troubled Debt Restructuring On Accrual Status
Financing Receivable, Impaired
Recorded investment	308				323
Consumer Portfolio Segment | Troubled Debt Restructuring On Nonaccrual Status
Financing Receivable, Impaired
Recorded investment	$ 46				$ 48

[1] Includes $ 277 , $ 642 and $ 308 , respectively, of commercial, residential mortgage and consumer portfolio TDRs on accrual status and $ 251 , $ 14 an d $ 46 , respectively, of commercial, residential mortgage and consumer portfolio TDRs on nonaccrual status at March 31, 2017 .

[2] Includes $ 322 , $ 635 and $ 323 , respectively, of commercial, residential mortgage and consumer portfolio TDR s on accrual status and $ 192 , $ 17 and $ 48 , respectively , of commercial, residential mortgage and consumer portfolio TDRs on nonaccrual status at December 31, 2016 .

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

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

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

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

[7] Excludes five restructured loans at March 31, 2017 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 $ 26 , a recorded investment of $ 26 and an ALLL of $ 18 .

[8] Excludes five restructured loans at December 31, 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 $ 26 , a recorded investment of $ 26 and an ALLL of $ 18 .