Reinsurance (Summary of Reinsurance Activity) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Insurance [Abstract]
Net assumed written premiums	$ 11.4	$ 12.9	$ 39.1	$ 43.3
Net premiums earned	12.9	12.2	38.2	34.2
Provision for claims	8.2	7.0	23.1	19.5
Amortization of capitalized acquisition costs	$ 0.2	$ 0.3	$ 0.9	$ 0.8