Subsequent Event (Subsequent Event - Additional Information) (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Subsequent Event
Shares acquired for treasury	$ 265	$ 335
Subsequent events | March 2016 Repurchase Program
Subsequent Event
Subsequent Events Date	Aug. 02, 2016
Shares acquired for treasury	$ 240
Redemption date	Aug. 05, 2016
Subsequent events | Vantiv, Inc.
Subsequent Event
Subsequent Events Date	Jul. 27, 2016
Amount Of Cash Flow Sales From 2019 To 2035	$ 331
Payment From Vantiv Inc to Bancorp To Terminate And Settle Certain Remaining TRA Cash Flows	171
Potential Termination And Settlement Of Tra Cash Flows	394
Pretax Gain Expected To Be Recognized	$ 163
Tra Obligations Settled If Options Exercised 2017	10.00%
Tra Obligations Settled If Options Exercised 2018	15.00%
Subsequent events | Vantiv, Inc. | Other Noninterest Income
Subsequent Event
Gain On Tax Receivable Agreement Termination And Settlement	$ 116
Subsequent events | Vantiv, Inc. | Lower Limit
Subsequent Event
Amount Of Cash Flow Sales From Years 2019 To 2035	2019
Subsequent events | Vantiv, Inc. | Upper Limit
Subsequent Event
Amount Of Cash Flow Sales From Years 2019 To 2035	2035