Federal Income Tax - Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Computed expected income tax expense (benefit)	$ 2,536	$ 20,337	$ (35,598)
The CARES Act	0	0	(18,562)
Tax-exempt municipal bond interest income	(3,115)	(3,412)	(3,669)
Nontaxable dividend income	(378)	(361)	(517)
Goodwill impairment	0	0	3,169
Compensation	582	770	695
Research & development credit	(1,591)	(1,545)	(2,045)
Other, net	(988)	460	(282)
Total	$ (2,954)	$ 16,249	$ (56,809)

Effective Income Tax Rate Reconciliation, Cares Act, Amount

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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