Consolidated Statements of Income and Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenues
Net premiums earned	$ 254,638	$ 231,262	$ 510,765	$ 465,490
Investment income, net of investment expenses	11,327	9,180	24,049	20,456
Net investment gains (losses) (includes reclassifications for net unrealized investment gains (losses) on available-for-sale securities of $(152) and $(692) in 2023 and $(716) and $(398) in 2022; previously included in accumulated other comprehensive income (loss))	1,124	(20,932)	(621)	(21,397)
Other income (loss)	0	26	0	1
Total revenues	267,089	219,536	534,193	464,550
Benefits, Losses and Expenses
Losses and loss settlement expenses	250,730	151,508	425,327	281,884
Amortization of deferred policy acquisition costs	59,156	52,538	118,991	103,009
Other underwriting expenses (includes reclassifications for employee benefit costs of $52 and $104 in 2023 and $900 and $1,800 in 2022; previously included in accumulated other comprehensive income (loss))	28,633	28,754	60,509	57,398
Interest expense	797	797	1,594	1,594
Total benefits, losses and expenses	339,316	233,597	606,421	443,885
Income (loss) before income taxes	(72,227)	(14,061)	(72,228)	20,665
Federal income tax expense (benefit) (includes reclassifications of $43 and $167 in 2023 and $339 and $461 in 2022; previously included in accumulated other comprehensive income (loss))	(15,845)	(3,604)	(16,540)	2,773
Net Income (loss)	(56,382)	(10,457)	(55,688)	17,892
Other comprehensive income (loss)
Change in net unrealized appreciation on investments	(19,616)	(50,691)	(1,612)	(133,656)
Change in liability for underfunded employee benefit plans	(820)	(4,591)	(1,640)	(9,183)
Other comprehensive income (loss), before tax and reclassification adjustments	(20,436)	(55,282)	(3,252)	(142,839)
Income tax effect	4,293	11,609	684	29,997
Other comprehensive income (loss), after tax, before reclassification adjustments	(16,143)	(43,673)	(2,568)	(112,842)
Reclassification adjustment for net investment losses included in income	152	716	692	398
Reclassification adjustment for employee benefit costs included in expense	(52)	(900)	(104)	(1,800)
Total reclassification adjustments, before tax	204	1,616	796	2,198
Income tax effect	43	339	167	461
Total reclassification adjustments, after tax	161	1,277	629	1,737
Comprehensive income (loss)	$ (72,364)	$ (52,853)	$ (57,627)	$ (93,213)
Diluted weighted average common shares outstanding (in shares)	25,249,073	25,148,143	25,234,834	25,410,649
Earnings Per Share [Abstract]
Basic (in dollars per share)	$ (2.23)	$ (0.42)	$ (2.21)	$ 0.71
Diluted (in dollars per share)	$ (2.23)	$ (0.42)	$ (2.21)	$ 0.70