Consolidated Statements of Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Earned premiums, net	$ 437.6	$ 212.4	$ 200.0
Net investment income, affiliates	4.9	4.9	4.9
Other income, affiliates	2.1	1.9	2.0
Losses and loss expenses, net affiliates	293.3	250.8	162.5
Net Acquisition and Operating Expenses	313.0	156.9	172.7
Interest Expense Debt To Affiliates	$ 0.7	$ 0.7	$ 0.7