Income Taxes (Reconciliation of the Beginning and Ending Amounts of the Bancorp's Unrecognized Tax Benefits) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued
Unrecognized tax benefits at January 1		$ 13	[1]	$ 11	[1]	$ 7
Gross increases for tax positions taken during prior period		9		1		2
Gross decreases for tax positions taken during prior period		0		0		0
Gross increases for tax positions taken during current period		2		2		2
Settlements with taxing authorities		0		0		0
Lapse of applicable statute of limitations		0		(1)		0
Unrecognized tax benefits at December 31	[1]	$ 24		$ 13		$ 11

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