Credit Quality (Summary of the Credit Risk Profile of the Bancorp's Commercial Portfolio Segment by Class) (Detail) - USD ($) $ in Millions	Dec. 31, 2017		Dec. 31, 2016
Financing Receivable, Modifications
Total loans and leases	$ 91,833	[1]	$ 91,955	[2]
Commercial Portfolio Segment
Financing Receivable, Modifications
Total loans and leases	56,395		56,452
Commercial Portfolio Segment | Commercial and Industrial Loans
Financing Receivable, Modifications
Total loans and leases	41,170		41,676
Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-Occupied
Financing Receivable, Modifications
Total loans and leases	3,362		3,360
Commercial Portfolio Segment | Commercial Mortgage Loans, Nonowner-Occupied
Financing Receivable, Modifications
Total loans and leases	3,242		3,539
Commercial Portfolio Segment | Commercial Construction Loans
Financing Receivable, Modifications
Total loans and leases	4,553		3,903
Commercial Portfolio Segment | Commercial Leases
Financing Receivable, Modifications
Total loans and leases	4,068		3,974
Pass | Commercial Portfolio Segment
Financing Receivable, Modifications
Total loans and leases	53,612		53,274
Pass | Commercial Portfolio Segment | Commercial and Industrial Loans
Financing Receivable, Modifications
Total loans and leases	38,813		38,844
Pass | Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-Occupied
Financing Receivable, Modifications
Total loans and leases	3,207		3,168
Pass | Commercial Portfolio Segment | Commercial Mortgage Loans, Nonowner-Occupied
Financing Receivable, Modifications
Total loans and leases	3,117		3,466
Pass | Commercial Portfolio Segment | Commercial Construction Loans
Financing Receivable, Modifications
Total loans and leases	4,553		3,902
Pass | Commercial Portfolio Segment | Commercial Leases
Financing Receivable, Modifications
Total loans and leases	3,922		3,894
Special Mention | Commercial Portfolio Segment
Financing Receivable, Modifications
Total loans and leases	1,290		1,335
Special Mention | Commercial Portfolio Segment | Commercial and Industrial Loans
Financing Receivable, Modifications
Total loans and leases	1,115		1,204
Special Mention | Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-Occupied
Financing Receivable, Modifications
Total loans and leases	75		72
Special Mention | Commercial Portfolio Segment | Commercial Mortgage Loans, Nonowner-Occupied
Financing Receivable, Modifications
Total loans and leases	28		4
Special Mention | Commercial Portfolio Segment | Commercial Construction Loans
Financing Receivable, Modifications
Total loans and leases	0		1
Special Mention | Commercial Portfolio Segment | Commercial Leases
Financing Receivable, Modifications
Total loans and leases	72		54
Substandard | Commercial Portfolio Segment
Financing Receivable, Modifications
Total loans and leases	1,486		1,816
Substandard | Commercial Portfolio Segment | Commercial and Industrial Loans
Financing Receivable, Modifications
Total loans and leases	1,235		1,604
Substandard | Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-Occupied
Financing Receivable, Modifications
Total loans and leases	80		117
Substandard | Commercial Portfolio Segment | Commercial Mortgage Loans, Nonowner-Occupied
Financing Receivable, Modifications
Total loans and leases	97		69
Substandard | Commercial Portfolio Segment | Commercial Construction Loans
Financing Receivable, Modifications
Total loans and leases	0		0
Substandard | Commercial Portfolio Segment | Commercial Leases
Financing Receivable, Modifications
Total loans and leases	74		26
Doubtful | Commercial Portfolio Segment
Financing Receivable, Modifications
Total loans and leases	7		27
Doubtful | Commercial Portfolio Segment | Commercial and Industrial Loans
Financing Receivable, Modifications
Total loans and leases	7		24
Doubtful | Commercial Portfolio Segment | Commercial Mortgage Loans, Owner-Occupied
Financing Receivable, Modifications
Total loans and leases	0		3
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

[1] Excludes $ 137 of residential mortgage loans measured at fair value at December 31, 2017 .

[2] Excludes $ 143 of residential mortgage loans measured at fair value at December 31, 2016 .