Summary of the ALLL and Related Loans and Leases Classified by Portfolio Segment (Detail) - USD ($) $ in Millions	Mar. 31, 2016		Dec. 31, 2015		Mar. 31, 2015	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	$ 216	[1]	$ 235	[2]
Collectively evaluated for impairment	963	[1]	922	[2]
Unallocated	116	[1]	115	[2]
Total allowance for loan and lease losses	1,295	[3]	1,272	[3]	$ 1,300	$ 1,322
Individually evaluated for impairment	2,092	[4]	1,869	[5]
Collectively evaluated for impairment	91,351	[4]	90,544	[5]
Loans acquired with deteriorated credit quality	2	[4]	2	[5]
Total Loans and Leases	93,445	[6]	92,415	[7]
Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	102	[1],[8]	119	[2],[9]
Collectively evaluated for impairment	765	[1]	721	[2]
Total allowance for loan and lease losses	867	[1]	840	[2]	852	875
Individually evaluated for impairment	1,022	[4],[8]	815	[5],[9]
Collectively evaluated for impairment	56,659	[4]	55,341	[5]
Total Loans and Leases	57,681	[4]	56,156	[5]
Residential Mortgage Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	66	[1]	67	[2]
Collectively evaluated for impairment	32	[1]	33	[2]
Total allowance for loan and lease losses	98	[1]	100	[2]	103	104
Individually evaluated for impairment	655	[4]	630	[5]
Collectively evaluated for impairment	13,078	[4]	12,917	[5]
Loans acquired with deteriorated credit quality	2	[4]	2	[5]
Total Loans and Leases	13,735	[4]	13,549	[5]
Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	48	[1]	49	[2]
Collectively evaluated for impairment	166	[1]	168	[2]
Total allowance for loan and lease losses	214	[1]	217	[2]	241	237
Individually evaluated for impairment	415	[4]	424	[5]
Collectively evaluated for impairment	21,614	[4]	22,286	[5]
Total Loans and Leases	22,029	[4]	22,710	[5]
Unallocated
Financing Receivable, Allowance for Credit Losses [Line Items]
Unallocated	116	[1]	115	[2]
Total allowance for loan and lease losses	$ 116	[1]	$ 115	[2]	$ 104	$ 106

[1] Includes $5 related to leveraged leases at March 31, 2016.

[2] Includes $5 related to leveraged leases at December 31, 2015.

[3] Includes $147 and $152 of cash and due from banks, $2,178 and $2,537 of portfolio loans and leases, $(27) and $(28) of ALLL, $11 and $14 of other assets, $4 and $3 of other liabilities, and $2,102 and $2,487 of long-term debt from consolidated VIEs that are included in their respective captions above at March 31, 2016 and December 31, 2015, respectively. For further information refer to Note 9.

[4] Excludes $160 of residential mortgage loans measured at fair value, and includes $812 of leveraged leases, net of unearned income at March 31, 2016.

[5] Excludes $167 of residential mortgage loans measured at fair value, and includes $801 of leveraged leases, net of unearned income at December 31, 2015.

[6] Excludes $160 of residential mortgage loans measured at fair value at March 31, 2016.

[7] Excludes $167 of residential mortgage loans measured at fair value at December 31, 2015.

[8] Includes five restructured loans at March 31, 2016 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 $27 and an ALLL of $15.

[9] Includes five restructured loans at December 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 a recorded investment of $27 and an ALLL of $15.