Acquisition and Discontinued Operations (Details 6) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Combined results of the discontinued operations
Net interest income	$ 553	$ 597
Net interest income (expense) after provision for loan and lease losses	511	637
Noninterest income	(472)	(457)
Noninterest expense	703	701
Income taxes	75	111
Income (loss) from discontinued operations, net of taxes	(5)	(11)
Segment, Discontinued Operations [Member]
Combined results of the discontinued operations
Net interest income	31	36
Provision for loan and lease losses	4	32
Net interest income (expense) after provision for loan and lease losses	27	4
Noninterest income	(18)	(9)
Noninterest expense	17	12
Income (loss) before income taxes	(8)	(17)
Income taxes	(3)	(6)
Income (loss) from discontinued operations, net of taxes	$ (5)	$ (11)