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, 2012		Dec. 31, 2011
Nonaccrual loans	$ 519		$ 860
Reduced-rate loans	22	[1]	27	[1]
Total nonperforming loans	541		887
Foreclosed property	54		94
Total nonperforming assets	595		981
Retail loans
Nonaccrual loans	105		82
Reduced-rate loans	16		19
Business loans
Nonaccrual loans	414		778
Reduced-rate loans	$ 6		$ 8

[1] Reduced-rate business loans totaled $6 million and $8 million, respectively, and reduced-rate retail loans totaled $16 million and $19 million, respectively, at December 31, 2012 and 2011.