Investments Investments - Net Realized Gains on Sales of Investments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Fixed Maturities [Member]
Net Investment Income [Line Items]
Gains on Sales	$ 3.9	$ 0.4	$ 5.9	$ 4.8
Losses on Sales	(0.5)	0.0	(0.6)	0.0
Equity Securities [Member]
Net Investment Income [Line Items]
Gains on Sales	31.4	3.0	32.9	3.8
Losses on Sales	$ (0.7)	$ 0.0	$ (0.7)	$ 0.0