Credit Quality (Summary of Average Impaired Loans and Leases and Interest Income by Class) (Parenthetical) (Detail) $ in Millions	3 Months Ended				6 Months Ended				12 Months Ended
	Jun. 30, 2017 USD ($)		Jun. 30, 2016 USD ($)		Jun. 30, 2017 USD ($)		Jun. 30, 2016 USD ($)		Dec. 31, 2016
Financing Receivable, Impaired
Average Recorded Investment	$ 1,743		$ 2,045		$ 1,796		$ 1,978
Number of contracts	2,430	[1],[2]	2,669	[3],[4]	4,489	[5],[6]	5,679	[7],[8]
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied
Financing Receivable, Impaired
Average Recorded Investment	$ 38	[9]	$ 68	[10]	$ 42	[9]	$ 69	[10]
Number of contracts	2	[1],[2]	3	[3],[4]	7	[5],[6]	10	[7],[8]
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied | Variable Interest Entity, Primary Beneficiary
Financing Receivable, Impaired
Average Recorded Investment	$ 26		$ 27		$ 26		$ 27
Number of contracts	5		5		5		5		5

[1] Represents number of loans post-modification and excludes loans previously modified in a TDR .

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

[3] Represents number of loans post-modification and excludes loans previously modified in a TDR .

[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 and excludes loans previously modified in a TDR .

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

[7] Represents number of loans post-modification and excludes loans previously modified in a TDR .

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

[9] (a) Excludes five restructured loans associated with a consolidated VIE in which the Bancorp has no continu ing credit risk due to the risk being assumed by a third party, with an average recorded investment of $ 2 6 and an immaterial amount of interest income recognized for both the three and six months ended June 30, 2017

[10] (a) Excludes five restructured loans 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 average recorded investment of $ 27 and an immaterial amount of interest income recognized for both the three and six months ended June 30, 2016 .