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
	Mar. 31, 2018		Mar. 31, 2017	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due
Total Past Due	$ 640	[1]		$ 638	[2]
30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	346	[1],[3]		333	[2],[4]
90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	294	[1],[3]		305	[2],[4]
Residential Mortgage Loans
Financing Receivable, Recorded Investment, Past Due
Portfolio loans and leases at fair value	136			137
Residential Mortgage Loans | Federal Housing Administration Loan
Financing Receivable, Recorded Investment, Past Due
Losses Due To Claim Denials And Curtailments	2		$ 2
Residential Mortgage Loans | Federal Housing Administration Loan | 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	79			95
Residential Mortgage Loans | Federal Housing Administration Loan | 90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	$ 317			$ 290

[1] Excludes $ 136 of residential mortgage loans measured at fair value at March 31, 2018 .

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

[3] Includes accrual and nonaccrual loans and leases.

[4] Includes accrual and nonaccrual loans and leases.