Consolidated Statements of Income and Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues
Net premiums earned	$ 280,859	$ 256,127
Investment income, net of investment expenses	16,342	12,722
Net investment gains (losses) (includes reclassifications for net unrealized investment gains (losses) on available-for-sale securities of $(2,564) in 2024 and $(540) in 2023; previously included in accumulated other comprehensive income (loss))	(1,202)	(1,745)
Other income (loss)	0	0
Total revenues	295,999	267,104
Benefits, Losses and Expenses
Losses and loss settlement expenses	179,646	174,597
Amortization of deferred policy acquisition costs	65,690	59,835
Other underwriting expenses (includes reclassifications for employee benefit costs of $0 in 2024 and $52 in 2023; previously included in accumulated other comprehensive income (loss))	32,465	30,303
Interest expense	859	797
Other nonunderwriting expenses	1,055	1,573
Total benefits, losses and expenses	279,715	267,105
Income (loss) before income taxes	16,284	(1)
Federal income tax expense (benefit) (includes reclassifications of $538 in 2024 and $124 in 2023; previously included in accumulated other comprehensive income (loss))	2,782	(695)
Net Income (loss)	13,502	694
Other comprehensive income (loss)
Change in net unrealized gain (loss) on investments	(11,096)	18,004
Change in liability for underfunded employee benefit plans	(724)	(820)
Foreign currency translation adjustment	(23)	0
Other comprehensive income (loss), before tax and reclassification adjustments	(11,843)	17,184
Income tax effect	2,482	(3,609)
Other comprehensive income (loss), after tax, before reclassification adjustments	(9,361)	13,575
Reclassification adjustment for net investment losses included in income	2,564	540
Reclassification adjustment for employee benefit costs included in expense	0	52
Total reclassification adjustments, before tax	2,564	592
Income tax effect	(538)	(124)
Total reclassification adjustments, after tax	2,026	468
Comprehensive income (loss)	$ 6,167	$ 14,737
Diluted weighted average common shares outstanding	25,834,494	25,500,115
Earnings Per Share [Abstract]
Basic (in dollars per share)	$ 0.53	$ 0.03
Diluted (in dollars per share)	$ 0.52	$ 0.03