Basis of Presentation Basis of Presentation (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Change in Accounting Estimate [Line Items]
Change in Accounting Estimate, Financial Effect on Policyholder Benefits and Claims Incurred	$ 490.2	$ 378.8	$ 1,362.5	$ 1,051.6
Change in Assumptions for Pension Plans [Member]
Change in Accounting Estimate [Line Items]
Change in Accounting Estimate, Financial Effect on Pension Expense			2.7
Change in Accounting Estimate, Use of Death Master File in Reserving Process [Member]
Change in Accounting Estimate [Line Items]
Change in Accounting Estimate, Financial Effect on Policyholder Benefits and Claims Incurred	$ 77.8		$ 77.8