Consolidated Statement of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands		Total	Common Stock	Additional paid-in capital	Retaining Earnings	Accumulated other comprehensive income
Balance, beginning (in shares) at Dec. 31, 2020			25,055,479
Balance, beginning of year at Dec. 31, 2020		$ 825,149	$ 25	$ 202,359	$ 555,854	$ 66,911
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		18,702			18,702
Shares repurchased (in shares)			(207)
Shares repurchased		(7)		(7)
Stock based compensation (in shares)			64,583
Stock based compensation		522		522
Dividends on common stock		(3,767)			(3,767)
Change in net unrealized investment appreciation (depreciation)	[1]	(23,456)				(23,456)
Change in liability for underfunded employee benefit plans	[2]	6,456				6,456
Balance, ending (in shares) at Mar. 31, 2021			25,119,855
Balance, ending of year at Mar. 31, 2021		823,599	$ 25	202,874	570,789	49,911
Balance, beginning (in shares) at Dec. 31, 2020			25,055,479
Balance, beginning of year at Dec. 31, 2020		825,149	$ 25	202,359	555,854	66,911
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		22,859
Balance, ending (in shares) at Sep. 30, 2021			25,080,923
Balance, ending of year at Sep. 30, 2021		814,529	$ 25	203,014	567,411	44,079
Balance, beginning (in shares) at Mar. 31, 2021			25,119,855
Balance, beginning of year at Mar. 31, 2021		823,599	$ 25	202,874	570,789	49,911
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		13,750			13,750
Shares repurchased (in shares)			(31,027)
Shares repurchased		(1,000)		(1,000)
Stock based compensation (in shares)			28,512
Stock based compensation		1,180		1,180
Dividends on common stock		(3,772)			(3,772)
Change in net unrealized investment appreciation (depreciation)	[1]	7,391				7,391
Change in liability for underfunded employee benefit plans	[2]	(1,674)				(1,674)
Balance, ending (in shares) at Jun. 30, 2021			25,117,340
Balance, ending of year at Jun. 30, 2021		839,474	$ 25	203,054	580,767	55,628
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(9,593)			(9,593)
Shares repurchased (in shares)			(36,417)
Shares repurchased		(1,001)		(1,001)
Stock based compensation		960		960
Dividends on common stock		(3,763)			(3,763)
Change in net unrealized investment appreciation (depreciation)	[1]	(9,828)				(9,828)
Change in liability for underfunded employee benefit plans	[2]	(1,721)				(1,721)
Balance, ending (in shares) at Sep. 30, 2021			25,080,923
Balance, ending of year at Sep. 30, 2021		$ 814,529	$ 25	203,014	567,411	44,079
Balance, beginning (in shares) at Dec. 31, 2021		25,082,104	25,082,104
Balance, beginning of year at Dec. 31, 2021		$ 879,121	$ 25	203,375	621,384	54,337
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		28,349			28,349
Stock based compensation (in shares)			37,140
Stock based compensation		631		631
Dividends on common stock		(3,767)			(3,767)
Change in net unrealized investment appreciation (depreciation)	[1]	(65,793)				(65,793)
Change in liability for underfunded employee benefit plans	[2]	(2,916)				(2,916)
Balance, ending (in shares) at Mar. 31, 2022			25,119,244
Balance, ending of year at Mar. 31, 2022		$ 835,625	$ 25	204,006	645,966	(14,372)
Balance, beginning (in shares) at Dec. 31, 2021		25,082,104	25,082,104
Balance, beginning of year at Dec. 31, 2021		$ 879,121	$ 25	203,375	621,384	54,337
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		$ (5,089)
Balance, ending (in shares) at Sep. 30, 2022		25,191,414	25,191,414
Balance, ending of year at Sep. 30, 2022		$ 700,795	$ 25	206,811	604,469	(110,510)
Balance, beginning (in shares) at Mar. 31, 2022			25,119,244
Balance, beginning of year at Mar. 31, 2022		835,625	$ 25	204,006	645,966	(14,372)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(10,457)			(10,457)
Stock based compensation (in shares)			67,404
Stock based compensation		2,159		2,159
Dividends on common stock		(4,028)			(4,028)
Change in net unrealized investment appreciation (depreciation)	[1]	(39,480)				(39,480)
Change in liability for underfunded employee benefit plans	[2]	(2,916)				(2,916)
Balance, ending (in shares) at Jun. 30, 2022			25,186,648
Balance, ending of year at Jun. 30, 2022		780,903	$ 25	206,165	631,481	(56,768)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(22,981)			(22,981)
Stock based compensation (in shares)			4,766
Stock based compensation		646		646
Dividends on common stock		(4,031)			(4,031)
Change in net unrealized investment appreciation (depreciation)	[1]	(50,826)				(50,826)
Change in liability for underfunded employee benefit plans	[2]	$ (2,916)				(2,916)
Balance, ending (in shares) at Sep. 30, 2022		25,191,414	25,191,414
Balance, ending of year at Sep. 30, 2022		$ 700,795	$ 25	$ 206,811	$ 604,469	$ (110,510)

[1] The change in net unrealized appreciation (depreciation) is net of reclassification adjustments and income taxes.

[2] The change in liability for underfunded employee benefit plans is net of reclassification adjustments and income taxes.