Investment Securities (Gains And Losses Related To Investment Securities) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Investments, Debt and Equity Securities [Abstract]
Gross realized gains from sales of available-for-sale securities	$ 24		$ 24		$ 75		$ 93
Gross realized losses from sales of available-for-sale securities	0	[1]	(9)	[1]	(46)		(12)	[1]
Gross losses from other-than-temporary impairment	(4)		(25)		(50)		(104)
Losses not related to credit	(2)	[2]	15	[2]	23	[2]	48	[2]
Gains (Losses) related to investment securities, net	18		5		2		25
Impairment associated with expected credit losses	(1)		(7)		(14)		(36)
Impairment Associated With Management's Intent To Sell The Impaired Securities Prior To Their Recovery In Value	0		0		0		(8)
Impairment associated with adverse changes in timing of expected future cash flows	5		3		13		12
Net impairment losses	$ (6)		$ (10)		$ (27)		$ (56)

[1] Loss for the nine months ended September 30, 2012 resulted from the sale of all of our Greek securities in the three months ended June 30, 2012, which were previously classified as held to maturity. The sale was undertaken as a result of the effect of significant deterioration in the creditworthiness of the underlying collateral, including significant downgrades of the securities' published credit ratings.

[2] Amount for the three months ended September 30, 2012 represented reversals of other-than-temporary impairment, or OTTI, not related to credit, previously recorded and recognized as a component of other comprehensive income, or OCI, which exceeded OTTI related to credit for the current period.