Condensed Statement of Comprehensive Income - Parent Company Only (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net income	$ 1,576	$ 1,297	$ 753
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Unrealized holding gains (losses) on cash flow hedge derivatives arising during period	24	58	1
Other Comprehensive Income (Loss) Net Of Tax	(95)	156	73
Comprehensive income	1,479	1,454	826
Comprehensive income attributable to noncontrolling interests	(2)	1
Comprehensive income attributable to Bancorp	1,481	1,453	826
Parent Company [Member]
Net income	1,576	1,297	753
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Unrealized holding gains (losses) on cash flow hedge derivatives arising during period	3	2	(4)
Other Comprehensive Income (Loss) Net Of Tax	3	2	(4)
Comprehensive income	1,579	1,299	749
Comprehensive income attributable to noncontrolling interests	(2)	1
Comprehensive income attributable to Bancorp	$ 1,581	$ 1,298	$ 749