Investment Income And Gains And Losses (Change In Net Unrealized Gains/Losses) (Details) (USD $) In Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2011		Dec. 31, 2010
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total	$ 417		$ 796
Deferred income tax charged (credited)	132		213
Change in unrealized gains (losses), net	285	[1]	583	[1]
Fixed-Maturity Investments [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total	434		749
Other Long Term Investments [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total	(17)		47
Variable Interest Entity, Primary Beneficiary [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Net unrealized gains due to transition adjustments			$ 266

[1] The annual change as of December 31, 2010 included $266 million of net unrealized gains due to the transition adjustment for the adoption of the accounting principles for consolidation of VIEs.