Consolidated Balance Sheet (Unaudited) (Parenthetical) (USD $) In Millions, except Share data	Sep. 30, 2011	Dec. 31, 2010
Investments:
Fixed maturities, available for sale at amortized cost	$ 20,297	$ 18,490
Equity securities, at cost	$ 775	$ 458
Shareholders' equity:
Common Stock, par value
Common Stock, shares authorized	200,000,000	200,000,000
Common Stock, shares outstanding	98,506,233	105,168,366