Consolidated Statement of Stockholders' Equity - USD ($) $ in Thousands		Total	Common Stock	Additional paid-in capital	Retaining earnings	Accumulated other comprehensive income (loss)
Balance, beginning of year (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)		80,594			80,594
Shares repurchased (in shares)			(67,651)
Shares repurchased		(2,007)		(2,007)
Stock based compensation (in shares)			94,276
Stock based compensation		3,023		3,023
Dividends on common stock		(15,064)			(15,064)
Change in net unrealized investment appreciation	[1]	(33,301)				(33,301)
Change in liability for underfunded employee benefit plans	[2]	20,727				20,727
Balance, ending of year (in shares) at Dec. 31, 2021			25,082,104
Balance, end 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)		15,031			15,031
Stock based compensation (in shares)			128,437
Stock based compensation		3,655		3,655
Dividends on common stock		(15,860)			(15,860)
Change in net unrealized investment appreciation	[1]	(138,138)				(138,138)
Change in liability for underfunded employee benefit plans	[2]	$ (3,695)				(3,695)
Balance, ending of year (in shares) at Dec. 31, 2022		25,210,541	25,210,541
Balance, end of year at Dec. 31, 2022		$ 740,114	$ 25	207,030	620,555	(87,496)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(29,700)			(29,700)
Stock based compensation (in shares)			59,301
Stock based compensation		2,956		2,956
Dividends on common stock		(16,164)			(16,164)
Change in net unrealized investment appreciation	[1]	21,402				21,402
Change in liability for underfunded employee benefit plans	[2]	$ 15,137				15,137
Balance, ending of year (in shares) at Dec. 31, 2023		25,269,842	25,269,842
Balance, end of year at Dec. 31, 2023		$ 733,745	$ 25	$ 209,986	$ 574,691	$ (50,957)

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

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