Investment Securities (Gains And Losses Related To Investment Securities) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Investment Securities [Abstract]
Gross realized gains from sales of investment securities	$ 152		$ 1,330		$ 418
Gross realized losses from sales of investment securities	(12)		(1,385)		(50)
Losses from other-than-temporary impairment	(123)		(651)		(1,155)
Losses not related to credit	50	[1]	420	[1]	928	[1]
Gains (Losses) related to investment securities, net	67		(286)		141
Impairment associated with expected credit losses	(42)		(203)		(151)
Impairment associated with management's intent to sell the impaired securities prior to their recovery in value	(8)		(1)		(54)
Impairment associated with adverse changes in timing of expected future cash flows	(23)		(27)		(22)
Net impairment losses	$ (73)		$ (231)		$ (227)

[1] Pursuant to revised GAAP adopted on April 1, 2009, these losses were recorded, net of related taxes, a component of other comprehensive income; refer to note 12.