Summarizes the Bancorp's Recorded Investment in Impaired Loans and Related Allowance by Class (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended		3 Months Ended
	Dec. 31, 2014		Mar. 31, 2015		Mar. 31, 2014
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	2,457		$ 2,404
Recorded Investment	2,233	[1]	2,197	[2]
Allowance	295		285
Commercial Portfolio Segment | Variable Interest Entity, Primary Beneficiary
Financing Receivable, Impaired [Line Items]
Number of Contracts	5
Commercial Portfolio Segment | Commercial and Industrial Loans
Financing Receivable, Impaired [Line Items]
Allowance	149		150
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied
Financing Receivable, Impaired [Line Items]
Allowance	14	[3]	7	[4]
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied | Variable Interest Entity, Primary Beneficiary
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	28		28
Recorded Investment	28		28
Allowance	10		10
Number of Contracts			5		5
Commercial Portfolio Segment | Commercial Mortgage Loans, Nonowner-Occupied
Financing Receivable, Impaired [Line Items]
Allowance	4		5
Commercial Portfolio Segment | Troubled Debt Restructuring On Accrual Status
Financing Receivable, Impaired [Line Items]
Recorded Investment	869		774
Commercial Portfolio Segment | Troubled Debt Restructuring On Nonaccrual Status
Financing Receivable, Impaired [Line Items]
Recorded Investment	214		205
Residential Mortgage Loans
Financing Receivable, Impaired [Line Items]
Allowance	65		64
Residential Mortgage Loans | Troubled Debt Restructuring On Accrual Status
Financing Receivable, Impaired [Line Items]
Recorded Investment	485		538
Residential Mortgage Loans | Troubled Debt Restructuring On Nonaccrual Status
Financing Receivable, Impaired [Line Items]
Recorded Investment	33		31
Consumer Portfolio Segment | Troubled Debt Restructuring On Accrual Status
Financing Receivable, Impaired [Line Items]
Recorded Investment	420		405
Consumer Portfolio Segment | Troubled Debt Restructuring On Nonaccrual Status
Financing Receivable, Impaired [Line Items]
Recorded Investment	63		$ 59

[1] Includes $869, $485 and $420, respectively, of commercial, residential mortgage and consumer TDRs on accrual status; $214, $33 and $63, respectively, of commercial, residential mortgage and consumer TDRs on nonaccrual status. Excludes five restructured loans at December 31, 2014 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 $28, a recorded investment of $28, and an allowance of $10.

[2] Includes $774, $538 and $405, respectively, of commercial, residential mortgage and consumer TDRs on accrual status; $205, $31 and $59, respectively, of commercial, residential mortgage and consumer TDRs on nonaccrual status.

[3] Excludes five restructured loans at December 31, 2014 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 $28, a recorded investment of $28, and an allowance of $10.

[4] Excludes five restructured loans at March 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 $28, a recorded investment of $28, and an allowance of $10.