Reinsurance (Schedule of Trust Assets and Reinsurance Liabilities) (Details) - USD ($) $ in Millions		Sep. 30, 2019	Dec. 31, 2018
Trust Assets [Member]
Reinsurance [Line Items]
Restricted cash and cash equivalents		$ 0.4	$ 0.3
Restricted securities available for sale		59.8	58.6
Unearned Premium [Member]
Reinsurance [Line Items]
Accounts payable and accrued liabilities		44.2	43.3
Claims Reserve [Member]
Reinsurance [Line Items]
Accounts payable and accrued liabilities	[1]	$ 2.0	$ 1.6

[1] The claims reserve represents our liability for incurred-but-not-reported claims and is estimated based on historical claims experience.