Reserves for Unpaid Losses and Loss Adjustment Expenses (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Unfavorable Adjustment To Prior Years Liability For Unpaid Claims and Claims Adjustment Expense		$ 2.3		$ 18.1
Favorable Adjustment To Prior Years Liability For Unpaid Claims and Claims Adjustment Expense	2.2		3.6
Personal Lines Business Unit [Member]
Unfavorable Adjustment To Prior Years Liability For Unpaid Claims and Claims Adjustment Expense			2.9	17.2
E&S Commercial [Member]
Unfavorable Adjustment To Prior Years Liability For Unpaid Claims and Claims Adjustment Expense			1.1	3.4
General Aviation Business Unit [Member]
Favorable Adjustment To Prior Years Liability For Unpaid Claims and Claims Adjustment Expense			2.6	2.3
Standard Commercial P&C business unit [Member]
Favorable Adjustment To Prior Years Liability For Unpaid Claims and Claims Adjustment Expense			2.0	0.2
Workers Compensation Business Unit [Member]
Favorable Adjustment To Prior Years Liability For Unpaid Claims and Claims Adjustment Expense			0.8
Low Value Dwelling Homeowners Line Of Business [Member]
Unfavorable Adjustment To Prior Years Liability For Unpaid Claims and Claims Adjustment Expense			0.7
Auto Liability Claims Personal Lines Business Unit [Member]
Unfavorable Adjustment To Prior Years Liability For Unpaid Claims and Claims Adjustment Expense			2.2
Florida Personal Lines Claims [Member]
Unfavorable Adjustment To Prior Years Liability For Unpaid Claims and Claims Adjustment Expense				$ 10.1