Insurance Expenses (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Insurance Expenses [Abstract]
Commissions									$ 558.7	$ 425.6	$ 399.2
General Expenses									229.7	194.1	209.0
Taxes, Licenses and Fees									73.2	52.8	48.8
Total Costs Incurred									861.6	672.5	657.0
Policy Acquisition Costs:
Deferred									(481.5)	(351.6)	(314.9)
Amortized									377.1	318.3	299.3
Net Policy Acquisition Costs Deferred									(104.4)	(33.3)	(15.6)
Amortization of VOBA									143.3	5.1	5.9
Insurance Expenses	$ 273.2	$ 296.0	$ 171.2	$ 160.1	$ 159.1	$ 163.7	$ 163.5	$ 158.0	$ 900.5	$ 644.3	$ 647.3