Summary of the ALLL and Related Loans and Leases Classified by Portfolio Segment (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	$ 305	[1]	$ 378	[2]
Collectively evaluated for impairment	911	[1]	1,094	[2]
Unallocated	106	[1]	110	[2]
Total allowance for loan and lease losses	1,322	[1],[3]	1,582	[2],[3]	1,854	2,255
Individually evaluated for impairment	2,261	[4]	3,381	[5]
Collectively evaluated for impairment	87,713	[4]	85,137	[5]
Loans acquired with deteriorated credit quality	2	[4]	4	[5]
Total loans and leases	89,976	[4],[6]	88,522	[5],[7]
Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	179	[1],[8]	186	[2],[9]
Collectively evaluated for impairment	696	[1]	872	[2]
Total allowance for loan and lease losses	875	[1]	1,058	[2]	1,236	1,527
Individually evaluated for impairment	1,260	[4],[8]	1,560	[5],[9]
Collectively evaluated for impairment	52,693	[4]	50,486	[5]
Total loans and leases	53,953	[4]	52,046	[5]
Residential Mortgage Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	65	[1]	139	[2]
Collectively evaluated for impairment	39	[1]	50	[2]
Total allowance for loan and lease losses	104	[1]	189	[2]	229	227
Individually evaluated for impairment	518	[4]	1,325	[5]
Collectively evaluated for impairment	11,761	[4]	11,259	[5]
Loans acquired with deteriorated credit quality	2	[4]	4	[5]
Total loans and leases	12,281	[4]	12,588	[5]
Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	61	[1]	53	[2]
Collectively evaluated for impairment	176	[1]	172	[2]
Total allowance for loan and lease losses	237	[1]	225	[2]	278	365
Individually evaluated for impairment	483	[4]	496	[5]
Collectively evaluated for impairment	23,259	[4]	23,392	[5]
Total loans and leases	23,742	[4]	23,888	[5]
Unallocated
Financing Receivable, Allowance for Credit Losses [Line Items]
Unallocated	106	[1]	110	[2]
Total allowance for loan and lease losses	$ 106	[1]	$ 110	[2]	$ 111	$ 136

[1] Includes $6 related to leveraged leases.

[2] Includes $9 related to leveraged leases.

[3] At December 31, 2014 and 2013, includes $179 and $49 of cash and due from banks, $47 and $48 of commercial mortgage loans, $3,331 and $1,010 of automobile loans, $(22) and $(15) of ALLL, $25 and $13 of other assets, $5 and $1 of other liabilities, $3,434 and $1,048 of long-term debt from consolidated VIEs that are included in their respective captions. For further information, refer to Note 10.

[4] Excludes $108 of residential mortgage loans measured at fair value, and includes $874 of leveraged leases, net of unearned income.

[5] Excludes $92 of residential mortgage loans measured at fair value, and includes $881 of leveraged leases, net of unearned income.

[6] Excludes $108 of loans measured at fair value.

[7] Excludes $92 of loans measured at fair value.

[8] Includes five restructured nonaccrual 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 a recorded investment of $28 and an allowance of $10.

[9] Includes five restructured loans at December 31, 2013 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 a recorded investment of $28 and an allowance of $11.