CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Investments
Fixed Maturity Securities, Amortized Cost	$ 39,738.1	$ 38,803.4
Stockholders' Equity
Common Stock, Par	$ 0.10	$ 0.10
Common Stock, Authorized	725,000,000	725,000,000
Common Stock, Issued	302,386,463	301,834,556
Treasury Stock, Shares at Cost	58,964,507	49,524,849