Credit Quality And Allowance For Credit Losses (Schedule Of Nonaccrual, Reduced-Rate Loans And Foreclosed Property) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Nonaccrual loans	$ 860		$ 1,080
Reduced-rate loans	27	[1]	43	[1]
Total nonperforming loans	887		1,123
Foreclosed property	94		112
Total nonperforming assets	981		1,235
Business Loans [Member]
Nonaccrual loans	778		1,007
Reduced-rate loans	8		26
Retail Loans [Member]
Nonaccrual loans	82		73
Reduced-rate loans	$ 19		$ 17

[1] Reduced-rate business loans totaled $8 million and $26 million, respectively, and reduced-rate retail loans totaled $19 million and $17 million, respectively, at December 31, 2011 and 2010.