Reconciliation of the Beginning and Ending Amounts of the Bancorp's Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued [Abstract]
Unrecognized tax benefits at January 1		$ 11	[1]	$ 7	[1]	$ 18
Gross increases for tax positions taken during prior period		1		2		1
Gross decreases for tax positions taken during prior period						(7)
Gross increases for tax positions taken during current period		2		2		1
Settlements with taxing authorities						(5)
Lapse of applicable statute of limitations		(1)				(1)
Unrecognized tax benefits at December 31	[1]	$ 13		$ 11		$ 7

[1] Amounts represent unrecognized tax benefits that, if recognized, would affect the annual effective tax rate.