Condensed Consolidated Statements of Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Earned premiums, from affiliates	$ 113.4	$ 105.4
Net investment income, from affiliate	1.2	1.2
Losses and loss expenses, from affiliates	93.7	74.1
Net Acquisition and Operating Expenses, from affiliates	70.6	77.3
Interest Expense Debt To Affiliates	0.2	0.2
Interest Paid To Affiliates	$ 0.2	$ 0.2