Credit Quality (Summarizes the Bancorp's Recorded Investment in Portfolio Loans and Leases by Age and Class) (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2018		Sep. 30, 2017	Sep. 30, 2018		Sep. 30, 2017	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due
Loans measured at fair value on a recurring basis	$ 1,010		$ 848	$ 1,010		$ 848
Total Past Due	597	[1]		597	[1]		$ 638	[2]
30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	290			290			333
90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	307			307			305
Residential Mortgage Loans
Financing Receivable, Recorded Investment, Past Due
Loans measured at fair value on a recurring basis	172			172			137
Residential Mortgage Loans | Federal Housing Administration Loan
Financing Receivable, Recorded Investment, Past Due
Losses Due To Claim Denials And Curtailments	1		$ 1	4		$ 4
Residential Mortgage Loans | Federal Housing Administration Loan | 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	80			80			95
Residential Mortgage Loans | Federal Housing Administration Loan | 90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	$ 198			$ 198			$ 290

[1] Excludes $ 172 of residential mortgage loans measured at fair value at September 30, 2018 .

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