Investments in Qualified Affordable Housing Tax Credits (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Other noninterest expense
Schedule of Equity Method Investments [Line Items]
Pre-tax investment and impairment losses	[1]	$ 33	$ 30	$ 100	$ 89
Applicable income tax expense
Schedule of Equity Method Investments [Line Items]
Tax credits and other benefits		$ 51	$ 46	$ 156	$ 139

[1] The Bancorp did not recognize impairment losses resulting from the forfeiture or ineligibility of tax credits or other circumstances during the three and nine months ended September 30, 2015 and 2014.