Asset Quality - Allowance for Loan and Lease Losses (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Balance at beginning of period - continuing operations	$ 888	$ 1,230	$ 1,004	$ 1,604
Charge-offs	(141)	(157)	(404)	(566)
Recoveries	32	48	117	130
Net loans charged off	(109)	(109)	(287)	(436)
Provision for loan and lease losses from continuing operations	109	10	172	(38)
Foreign currency translation adjustment			(1)	1
Balance at end of period - continuing operations	$ 888	$ 1,131	$ 888	$ 1,131