Schedule VI - Supplemental Information Concerning Property-Casualty Insurance Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Supplemental Information For Property, Casualty Insurance Underwriters [Abstract]
Deferred Policy Acquisition Costs	$ 19,193	$ 20,366	$ 20,746
Reserves for Unpaid Claims and Claim Adjustment Expenses	481,567	450,878	415,135
Unearned Premiums	241,254	216,407	196,826
Earned Premiums	353,370	349,081	321,217
Net Investment Income	16,342	13,969	12,383
Claims and Claim Adjustment Expenses Incurred Related to Current Year	246,080	237,102	215,258
Claims and Claim Adjustment Expenses Incurred Related to Prior Years	7,608	(6,953)	(5,203)
Amortization of Deferred Policy Acquisition Costs	39,076	32,674	40,890
Paid Claims and Claims Adjustment Expenses	243,445	205,254	199,331
Premiums Written	$ 361,829	$ 356,944	$ 324,352