Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Amortized Cost of Fixed Maturity Securities	$ 4,342.6	$ 4,283.8
Available for sale Securities, Equity Securities, Cost	480.6	462.7
Fair Value of Notes Payable	$ 677.0	$ 675.5
Common Stock, Par Value	$ 0.1	$ 0.1
Common Stock, Shares Authorized	100,000,000	100,000,000
Common Stock, Shares Issued	58,321,766	58,454,390
Common Stock, Shares, Outstanding	58,321,766	58,454,390