Credit Quality (Summary of the Credit Risk Profile of the Bancorp's Commercial Portfolio Segment by Class) (Detail) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable, Modifications
Total loans and leases	$ 109,652	$ 95,086
Commercial and Industrial Loans
Financing Receivable, Modifications
Total loans and leases	51,862	44,340
Commercial Mortgage Loans, Owner-occupied
Financing Receivable, Modifications
Total loans and leases	4,412	3,284
Commercial Mortgage Loans, Nonowner-Occupied
Financing Receivable, Modifications
Total loans and leases	6,274	3,690
Commercial Construction Loans
Financing Receivable, Modifications
Total loans and leases	5,231	4,657
Commercial Leases
Financing Receivable, Modifications
Total loans and leases	3,909	3,600
Commercial Portfolio Segment
Financing Receivable, Modifications
Total loans and leases	71,688	59,571
Commercial Portfolio Segment | Commercial and Industrial Loans
Financing Receivable, Modifications
Total loans and leases	51,862	44,340
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied
Financing Receivable, Modifications
Total loans and leases	4,412	3,284
Commercial Portfolio Segment | Commercial Mortgage Loans, Nonowner-Occupied
Financing Receivable, Modifications
Total loans and leases	6,274	3,690
Commercial Portfolio Segment | Commercial Construction Loans
Financing Receivable, Modifications
Total loans and leases	5,231	4,657
Commercial Portfolio Segment | Commercial Leases
Financing Receivable, Modifications
Total loans and leases	3,909	3,600
Pass | Commercial Portfolio Segment
Financing Receivable, Modifications
Total loans and leases	68,673	57,581
Pass | Commercial Portfolio Segment | Commercial and Industrial Loans
Financing Receivable, Modifications
Total loans and leases	49,621	42,695
Pass | Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied
Financing Receivable, Modifications
Total loans and leases	4,133	3,122
Pass | Commercial Portfolio Segment | Commercial Mortgage Loans, Nonowner-Occupied
Financing Receivable, Modifications
Total loans and leases	5,924	3,632
Pass | Commercial Portfolio Segment | Commercial Construction Loans
Financing Receivable, Modifications
Total loans and leases	5,186	4,657
Pass | Commercial Portfolio Segment | Commercial Leases
Financing Receivable, Modifications
Total loans and leases	3,809	3,475
Special Mention | Commercial Portfolio Segment
Financing Receivable, Modifications
Total loans and leases	1,242	901
Special Mention | Commercial Portfolio Segment | Commercial and Industrial Loans
Financing Receivable, Modifications
Total loans and leases	995	779
Special Mention | Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied
Financing Receivable, Modifications
Total loans and leases	71	23
Special Mention | Commercial Portfolio Segment | Commercial Mortgage Loans, Nonowner-Occupied
Financing Receivable, Modifications
Total loans and leases	102	27
Special Mention | Commercial Portfolio Segment | Commercial Construction Loans
Financing Receivable, Modifications
Total loans and leases	36	0
Special Mention | Commercial Portfolio Segment | Commercial Leases
Financing Receivable, Modifications
Total loans and leases	38	72
Substandard | Commercial Portfolio Segment
Financing Receivable, Modifications
Total loans and leases	1,736	1,076
Substandard | Commercial Portfolio Segment | Commercial and Industrial Loans
Financing Receivable, Modifications
Total loans and leases	1,209	853
Substandard | Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied
Financing Receivable, Modifications
Total loans and leases	208	139
Substandard | Commercial Portfolio Segment | Commercial Mortgage Loans, Nonowner-Occupied
Financing Receivable, Modifications
Total loans and leases	248	31
Substandard | Commercial Portfolio Segment | Commercial Construction Loans
Financing Receivable, Modifications
Total loans and leases	9	0
Substandard | Commercial Portfolio Segment | Commercial Leases
Financing Receivable, Modifications
Total loans and leases	62	53
Doubtful | Commercial Portfolio Segment
Financing Receivable, Modifications
Total loans and leases	37	13
Doubtful | Commercial Portfolio Segment | Commercial and Industrial Loans
Financing Receivable, Modifications
Total loans and leases	37	13
Doubtful | Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-occupied
Financing Receivable, Modifications
Total loans and leases	0	0
Doubtful | Commercial Portfolio Segment | Commercial Mortgage Loans, Nonowner-Occupied
Financing Receivable, Modifications
Total loans and leases	0	0
Doubtful | Commercial Portfolio Segment | Commercial Construction Loans
Financing Receivable, Modifications
Total loans and leases	0	0
Doubtful | Commercial Portfolio Segment | Commercial Leases
Financing Receivable, Modifications
Total loans and leases	$ 0	$ 0