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, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax Contingency [Line Items]
Unrecognized tax benefits at January 1	$ 16	$ 82	$ 959
Gross increases for tax positions taken during prior period	1	4	16
Gross decreases for tax positions taken during prior period	(2)	(23)	(329)
Gross increases for tax positions taken during current period		2	1
Settlements with taxing authorities		(48)	(563)
Lapse of applicable statute of limitations	(1)	(1)	(2)
Unrecognized tax benefits at December 31	$ 14	$ 16	$ 82