Income Taxes (Income Tax Expense (Benefit) On Income (Loss) And Shareholders' Equity) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Taxes [Abstract]
Federal - Current taxes	$ (1)	$ 91	$ (488)
State - Current taxes	1	(17)	5
Foreign - Current taxes	15	(1)	(25)
Federal - Deferred taxes	(919)	(239)	1,046
State - Deferred taxes	0
Foreign - Deferred taxes	(16)	18	45
Provision (benefit) for income taxes	(920)	(148)	583
Total adjustments due to the adoption of new accounting standards		(21)	(3)
Change in unrealized gains and losses on investments	119	112	526
Change in other-than-temporary impairment losses	3	(4)	(50)
Change in fair value of derivative instruments	3	(7)	46
Change in foreign currency translation	(1)	2	4
Share-based compensation	4	3	5
Total income taxes charged (credited) to shareholders' equity	128	85	528
Total effect of income taxes	$ (792)	$ (63)	$ 1,111