Credit Quality (Summarizes the Bancorp's Recorded Investment in Portfolio Loans and Leases by Age and Class) (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017		Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due
Portfolio loans and leases at fair value	$ 137		$ 143
Total Past Due	638	[1]	616	[2]
30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	333	[1],[3]	315	[2],[4]
90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	305	[1],[3]	301	[2],[4]
Residential Mortgage
Financing Receivable, Recorded Investment, Past Due
Portfolio loans and leases at fair value	137		143
Residential Mortgage Loans
Financing Receivable, Recorded Investment, Past Due
Portfolio loans and leases at fair value	137		143
Residential Mortgage Loans | Federal Housing Administration Loan
Financing Receivable, Recorded Investment, Past Due
Losses Due To Claim Denials And Curtailments	5		6
Residential Mortgage Loans | Federal Housing Administration Loan | 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	95		110
Residential Mortgage Loans | Federal Housing Administration Loan | 90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	$ 290		$ 312

[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 .

[3] Includes accrual and nonaccrual loans and leases.

[4] Includes accrual and nonaccrual loans and leases .