Consolidated Balance Sheets (unaudited) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Fixed maturity securities, available-for-sale, at fair value	$ 10,123	$ 10,275
Common stock par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	135,083,637	137,928,552
Common stock, shares outstanding (in shares)	135,083,637	137,928,552
Accumulated other comprehensive income, tax provision	$ 127	$ 104
Deferred equity compensation (in shares)	320,193	320,193