Effects of Reinsurance on Premiums (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Insurance [Abstract]
Direct Premiums Written	$ 1,278,504	$ 1,148,190	$ 989,525
Assumed Premiums Written	101,764	104,211	51,323
Ceded Premiums Written	(633,275)	(512,270)	(447,329)
Premiums Written, Net	746,993	740,131	593,519
Increase (Decrease) in Direct Unearned Premiums	(59,660)	(49,048)	(49,386)
Increase (Decrease) in Assumed Unearned Premiums	12,918	(22,392)	(5,439)
Increase (Decrease) in Ceded Unearned Premiums	52,149	20,585	46,796
Increase (Decrease) in Unearned Premiums	5,407	(50,855)	(8,029)
Direct Premiums Earned, Property and Casualty	1,218,844	1,099,142	940,139
Assumed Premiums Earned, Property and Casualty	114,682	81,819	45,884
Ceded Premiums Earned	(581,126)	(491,685)	(400,533)
Premiums Earned, Net	752,400	689,276	585,490
Direct Losses and LAE Incurred	1,003,767	1,101,328	863,928
Assumed Losses and LAE Incurred	44,914	97,444	60,836
Ceded Losses and LAE Incurred	(549,188)	(790,183)	(559,229)
Net Losses and LAE Incurred	$ 499,493	$ 408,589	$ 365,535