Credit Quality And Allowance For Credit Losses (Changes In The Allowance For Loan Losses And Related Loan Amounts) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Balance at beginning of period	$ 901	$ 985	$ 770
Loan charge-offs	(423)	(627)	(895)
Recoveries on loans previously charged-off	95	63	27
Net loan charge-offs	(328)	(564)	(868)
Provision for loan losses	153	480	1,082
Foreign currency translation adjustment	0	0	1
Balance at end of period	726	901	985
As a percentage of total loans	1.70%	2.24%	2.34%
Allowance for loan losses individually evaluated for impairment	153	197	193
Allowance for loan losses collectively evaluated for impairment	573	704	792
Allowance for PCI loans	0	0	0
Total allowance for loan losses	726	901	985
Loans individually evaluated for impairment	771	974	986
Loans collectively evaluated for impairment	41,821	39,262	41,175
PCI loans	87	0	0
Total loans	42,679	40,236	42,161
Business Loans [Member]
Balance at beginning of period	824	915
Loan charge-offs	(375)	(574)
Recoveries on loans previously charged-off	89	58
Net loan charge-offs	(286)	(516)
Provision for loan losses	110	425
Foreign currency translation adjustment	0	0
Balance at end of period	648	824
As a percentage of total loans	1.67%	2.27%
Allowance for loan losses individually evaluated for impairment	149	192
Allowance for loan losses collectively evaluated for impairment	499	632
Allowance for PCI loans	0	0
Total allowance for loan losses	648	824
Loans individually evaluated for impairment	719	927
Loans collectively evaluated for impairment	38,068	35,379
PCI loans	81	0
Total loans	38,868	36,306
Retail Loans [Member]
Balance at beginning of period	77	70
Loan charge-offs	(48)	(53)
Recoveries on loans previously charged-off	6	5
Net loan charge-offs	(42)	(48)
Provision for loan losses	43	55
Foreign currency translation adjustment	0	0
Balance at end of period	78	77
As a percentage of total loans	2.04%	1.96%
Allowance for loan losses individually evaluated for impairment	4	5
Allowance for loan losses collectively evaluated for impairment	74	72
Allowance for PCI loans	0	0
Total allowance for loan losses	78	77
Loans individually evaluated for impairment	52	47
Loans collectively evaluated for impairment	3,753	3,883
PCI loans	6	0
Total loans	$ 3,811	$ 3,930