Stockholders' Equity (Schedule Of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012		Dec. 31, 2011
Stockholders' Equity [Abstract]
Net unrealized gains (losses) on securities	$ 288	[1]	$ 294	[1]
Net unrecognized elements of defined benefit plans	(43)		(43)
Foreign currency translation adjustments	6		(49)
Unrealized losses on cash flow hedging instruments	(25)		(26)
Other-than-temporary impairment not recognized in earnings on securities	44		10
Initial application of measurement date provisions for postretirement benefits other than pensions	(1)		(1)
Initial application from adoption of consolidation standards	(16)		(16)
Total accumulated other comprehensive income	253		169
Unrealized losses not related to credit on other-than-temporarily impaired securities, net of income tax	116		170
Income tax expense on unrealized losses not related to credit on other-than-temporarily impaired securities	74		109
Deferred tax related to accumulated other comprehensive income	$ 148		$ 142

[1] Includes net unrealized gains (losses) on securities available for sale and retained subordinated notes. Unrealized losses not related to credit on other-than-temporarily impaired securities of $116 million (net of income tax of $74 million) and $170 million (net of income tax of $109 million) were reported in other comprehensive income as of March 31, 2012 and December 31, 2011, respectively.