Summary of the ALLL and Related Loans and Leases Classified by Portfolio Segment (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014		Jun. 30, 2014	Dec. 31, 2013		Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	$ 388	[1]		$ 378	[2]
Collectively evaluated for impairment	927	[1]		1,094	[2]
Unallocated	99	[1]		110	[2]
Total allowance for loan and lease losses	1,414	[3]	1,458	1,582	[3]	1,677	1,735	1,854
Individually evaluated for impairment	3,067	[4]		3,381	[5]
Collectively evaluated for impairment	87,444	[4]		85,137	[5]
Loans acquired with deteriorated credit quality	4	[4]		4	[5]
Total Loans and Leases	90,515	[6]		88,522	[7]
Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	199	[1],[8]		186	[2],[9]
Collectively evaluated for impairment	714	[1]		872	[2]
Total allowance for loan and lease losses	913	[1]	961	1,058	[2]	1,147	1,183	1,236
Individually evaluated for impairment	1,343	[4],[8]		1,560	[5],[9]
Collectively evaluated for impairment	52,549	[4]		50,486	[5]
Total Loans and Leases	53,892	[4]		52,046	[5]
Residential Mortgage Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	127	[1]		139	[2]
Collectively evaluated for impairment	37	[1]		50	[2]
Total allowance for loan and lease losses	164	[1]	174	189	[2]	194	201	229
Individually evaluated for impairment	1,250	[4]		1,325	[5]
Collectively evaluated for impairment	11,578	[4]		11,259	[5]
Loans acquired with deteriorated credit quality	4	[4]		4	[5]
Total Loans and Leases	12,832	[4]		12,588	[5]
Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	62	[1]		53	[2]
Collectively evaluated for impairment	176	[1]		172	[2]
Total allowance for loan and lease losses	238	[1]	221	225	[2]	235	247	278
Individually evaluated for impairment	474	[4]		496	[5]
Collectively evaluated for impairment	23,317	[4]		23,392	[5]
Total Loans and Leases	23,791	[4]		23,888	[5]
Unallocated
Financing Receivable, Allowance for Credit Losses [Line Items]
Unallocated	99	[1]		110	[2]
Total allowance for loan and lease losses	$ 99	[1]	$ 102	$ 110	[2]	$ 101	$ 104	$ 111

[1] Includes $7 related to leveraged leases.

[2] Includes $9 related to leveraged leases.

[3] Includes $150 and $49 of cash and due from banks, $48 and $48 of commercial mortgage loans, $2,785 and $1,010 of automobile loans, $(19) and $(15) of ALLL, $26 and $13 of other assets, $7 and $1 of other liabilities, and $2,882 and $1,048 of long-term debt from consolidated VIEs that are included in their respective captions above at September 30, 2014 and December 31, 2013, respectively. See Note 10.

[4] Excludes $109 of residential mortgage loans measured at fair value, and includes $880 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 $109 of loans measured at fair value.

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

[8] Includes five restructured loans at September 30, 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.