Credit Quality (Summary of the Credit Risk Profile of the Bancorp's Residential Mortgage and Consumer Portfolio Segments by Class) (Parenthetical) (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Residential Mortgage Loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Portfolio loans and leases at fair value	$ 162	$ 137

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-URI http://asc.fasb.org/subtopic&trid=2196772

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant