Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions	$ 3.6
Income Tax Benefit Recognized from a Reduction in Liability for Unrecognized Tax Benefits	$ 2.3
Income taxes paid		$ 44.4	$ 37.2	$ 42.4
Interest on income taxes expense		(3.3)	$ 0.4	$ 0.4
Mutual Savings Life [Member]
Mutual Savings Life’s income		14.7
Amount of tax the company will have to pay if the Mutual Savings Life's income is distributes to shareholders in the future		$ 5.1