Summary of the ALLL and Related Loans and Leases Classified by Portfolio Segment (Parenthetical) (Detail) $ in Millions	6 Months Ended				12 Months Ended
	Jun. 30, 2015 USD ($) number		Jun. 30, 2014 USD ($)		Dec. 31, 2014 USD ($) number		Mar. 31, 2015 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	$ 1,293	[1]	$ 1,458		$ 1,322	[1]	$ 1,300	$ 1,483	$ 1,582
Portfolio loans and leases	$ 92,525	[2]			89,976	[3]
Number of Contracts	7,676	[4],[5]	4,698	[6],[7]
Recorded Investment	$ 2,124	[8]			2,233	[9]
Variable Interest Entity, Primary Beneficiary
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	$ 29				$ 22
Number of Contracts | number	5				5
Commercial | Variable Interest Entity, Primary Beneficiary
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	$ 16				$ 10
Number of Contracts | number	5				5
Recorded Investment	$ 28				$ 28
Leveraged Leases
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan and lease losses	5				6
Portfolio loans and leases	880				874
Residential Mortgage Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Portfolio loans and leases at fair value	$ 178				$ 108

[1] Includes $156 and $179 of cash and due from banks, $2,547 and $3,378 of portfolio loans and leases, $(29) and $(22) of ALLL, $23 and $25 of other assets, $4 and $5 of other liabilities, and $2,542 and $3,434 of long-term debt from consolidated VIEs that are included in their respective captions above at June 30, 2015 and December 31, 2014, respectively. For further information refer to Note 10.

[2] Excludes $178 of residential mortgage loans measured at fair value.

[3] Excludes $108 of residential mortgage loans measured at fair value.

[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.

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

[8] Includes $769, $576 and $394, respectively, of commercial, residential mortgage and consumer TDRs on accrual status; $175, $27 and $56, respectively, of commercial, residential mortgage and consumer TDRs on nonaccrual status.

[9] 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.