Credit Quality (Summary of Average Impaired Loans and Leases and Interest Income by Class) (Parenthetical) (Detail) $ in Millions		3 Months Ended				12 Months Ended
		Mar. 31, 2017 USD ($)		Mar. 31, 2016 USD ($)		Dec. 31, 2016
Financing Receivable, Impaired
Average Recorded Investment		$ 1,835		$ 1,954
Number of contracts		2,059	[1],[2]	3,010	[3],[4]
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied
Financing Receivable, Impaired
Average Recorded Investment	[5]	$ 43		$ 71
Number of contracts		5	[1],[2]	7	[3],[4]
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied | Variable Interest Entity, Primary Beneficiary
Financing Receivable, Impaired
Average Recorded Investment		$ 26		$ 27
Number of contracts		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] (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 $ 2 6 and $ 27 at March 31, 2017 and March 31, 2016 , respectively, and an immaterial amount of interest income recognized for the both the three months ended March 31, 2017 and March 31, 2016 .