Asset Quality (Details 8) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Summary of allowance for loan and lease losses
Balance at beginning of period - continuing operations	$ 1,604	$ 2,534	$ 1,629
Charge-offs	(715)	(1,822)	(2,396)
Recoveries	174	252	139
Net loans charged off	(541)	(1,570)	(2,257)
Provision for loan and lease losses from continuing operations	(60)	638	3,159
Foreign currency translation adjustment	1	2	3
Balance at end of period - continuing operations	$ 1,004	$ 1,604	$ 2,534