Consolidated Balance Sheet (Unaudited) (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Consolidated Balance Sheet [Abstract]
Fixed maturities, available for sale at amortized cost	$ 20,994	$ 20,562
Equity securities, at cost	$ 800	$ 744
Common Stock, par value
Common Stock, shares authorized	200,000,000	200,000,000
Common Stock, shares outstanding	97,177,820	97,846,402