Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Fixed maturity securities, available-for-sale, at fair value	$ 9,363	$ 9,346
Common stock Par Value (per share)	$ 0.01	$ 0.01
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	192,337,826	194,003,297
Common stock, shares outstanding	192,337,826	194,003,297
Accumulated other comprehensive income, tax provision	$ 169	$ 198
Deferred equity compensation, shares	320,193	320,193