VOBA And Other Intangible Assets (Information About VOBA) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Movement in Present Value of Future Insurance Profits [Roll Forward]
Beginning balance	$ 32.1	$ 41.2	$ 45.5
Additions	0.0	0.0	4.1
Amortization, net of interest accrued	(7.9)	(9.2)	(8.3)
Foreign currency translation and other	0.2	0.1	(0.1)
Ending balance	$ 24.4	$ 32.1	$ 41.2