Reconciliation of the Beginning and Ending Amounts of the Bancorp's Unrecognized Tax Benefits (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Contingency [Line Items]
Unrecognized tax benefits at January 1	$ 14	$ 16	$ 82
Gross increases for tax positions taken during prior period	6	1	4
Gross decreases for tax positions taken during prior period	(3)	(2)	(23)
Gross increases for tax positions taken during current period	2		2
Settlements with taxing authorities			(48)
Lapse of applicable statute of limitations	(1)	(1)	(1)
Unrecognized tax benefits at December 31	$ 18	$ 14	$ 16