Investment Securities (Schedule Of Credit-Related Loss Activity Recognized In Earnings) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010		Dec. 31, 2009
Investment Securities [Abstract]
Beginning balance	$ 63	$ 175	[1]
Plus expected credit-related losses for which other-than-temporary impairment was not previously recognized	10	88		214	[1]
Plus expected credit-related losses for which other-than-temporary impairment was previously recognized	55	142
Less losses realized for securities sold	(13)	(342)		(17)	[1]
Less losses related to securities intended or required to be sold	(2)			(22)	[1]
Ending balance	$ 113	$ 63		$ 175	[1]

[1] Beginning balance was as of April 1, 2009, pursuant to revised GAAP.