Credit Quality (Summarizes the Bancorp's Recorded Investment in Impaired Loans and Related Allowance by Class) (Parenthetical) (Detail) $ in Millions	3 Months Ended				6 Months Ended				12 Months Ended
	Jun. 30, 2018 USD ($)		Jun. 30, 2017		Jun. 30, 2018 USD ($)		Jun. 30, 2017	[7],[8],[9],[10]	Dec. 31, 2017 USD ($)
Financing Receivable, Impaired
Unpaid principal balance	$ 1,589				$ 1,589				$ 1,679
Recorded investment	1,485	[1]			1,485	[1]			1,545	[2]
Allowance	$ 178				$ 178				200
Number of contracts	2,273	[3],[4],[5],[6]	2,430	[7],[8],[9],[10]	4,544	[3],[4],[5],[6]	4,489
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied
Financing Receivable, Impaired
Allowance	$ 1				$ 1				$ 7
Number of contracts			2	[7],[8],[9],[10]	2	[3],[4],[5],[6]	7
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied | Variable Interest Entity, Primary Beneficiary
Financing Receivable, Impaired
Number of contracts			5						5
Commercial Portfolio Segment | Troubled Debt Restructuring On Accrual Status
Financing Receivable, Impaired
Recorded investment	104				$ 104				$ 249
Commercial Portfolio Segment | Troubled Debt Restructuring On Nonaccrual Status
Financing Receivable, Impaired
Recorded investment	173				173				150
Residential Mortgage Loans
Financing Receivable, Impaired
Allowance	$ 65				$ 65				64
Number of contracts	537	[3],[4],[5],[6]	199	[7],[8],[9],[10]	784	[3],[4],[5],[6]	402
Residential Mortgage Loans | Troubled Debt Restructuring On Accrual Status
Financing Receivable, Impaired
Recorded investment	$ 773				$ 773				652
Residential Mortgage Loans | Troubled Debt Restructuring On Nonaccrual Status
Financing Receivable, Impaired
Recorded investment	15				15				13
Consumer Portfolio Segment | Troubled Debt Restructuring On Accrual Status
Financing Receivable, Impaired
Recorded investment	251				251				275
Consumer Portfolio Segment | Troubled Debt Restructuring On Nonaccrual Status
Financing Receivable, Impaired
Recorded investment	$ 46				$ 46				$ 45

[1] Includes $ 104 , $ 773 and $ 251 , respectively, of commercial, residential mortgage and consumer portfolio TDRs on accrual status and $ 173 , $ 15 an d $ 46 , respectively, of commercial, residential mortgage and consumer portfolio TDRs on nonaccrual status at June 30, 2018 .

[2] Includes $ 249 , $ 652 and $ 275 , respectively, of commercial, residential mortgage and consumer portfolio TDR s on accrual status and $ 150 , $ 13 and $ 45 , respectively , of commercial, residential mortgage and consumer portfolio TDRs on nonaccrual status at December 31, 2017 .

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

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

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

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

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

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