Consolidated Statements of Income (Loss) (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Gross Written Premiums	$ 455,943	$ 402,038	$ 1,448,403	$ 1,304,522
Revenues:
Net Written Premiums	352,412	296,016	1,124,966	966,461
Change in Unearned Premiums	(5,374)	5,339	(124,286)	(85,140)
Net Earned Premiums	347,038	301,355	1,000,680	881,321
Net Investment Income	25,651	22,598	73,954	66,311
Net Realized and Unrealized Gains (Losses):
Total Other-Than-Temporary Impairment Losses	(15)	(957)	(71)	(2,005)
Portion of Loss Recognized in Other Comprehensive Income	15	(15)	71	(60)
Net Other-Than-Temporary Impairment Losses Recognized in Earnings	0	(972)	0	(2,065)
Net Realized Gains on Investments Sold	253	5,190	3,210	7,933
Net Unrealized Gains on Equity Securities	2,310		457
Total Net Realized and Unrealized Gains	2,563	4,218	3,667	5,868
Other Income (Loss)	1,724	(1,699)	4,235	(1,042)
Total Revenues	376,976	326,472	1,082,536	952,458
Expenses:
Net Losses and Loss Adjustment Expenses	240,900	276,171	623,378	622,881
Commission Expenses	57,999	45,509	165,344	141,526
Other Operating Expenses	67,584	45,773	198,692	165,077
Merger Transaction Costs	2,439		2,439
Interest Expense	3,891	3,862	11,619	11,584
Total Expenses	372,813	371,315	1,001,472	941,068
Income (Loss) Before Income Taxes	4,163	(44,843)	81,064	11,390
Income Tax Expense (Benefit)	(462)	(16,864)	13,457	(2,243)
Net Income (Loss)	$ 4,625	$ (27,979)	$ 67,607	$ 13,633
Net Income (Loss) per Common Share:
Basic	$ 0.16	$ (0.95)	$ 2.28	$ 0.46
Diluted	$ 0.15	$ (0.95)	$ 2.24	$ 0.45
Average common shares outstanding:
Basic	29,768	29,500	29,699	29,419
Diluted	30,184	29,500	30,160	30,006