Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive (Loss) Income, Net of Taxes	Retained Earnings	Treasury Stock	Total
Balance at Dec. 31, 2020	$ 178	$ 209,779	$ 53,527	$ 745,029	$ (123,834)	$ 884,679
Net income				36,174		36,174
Unrealized losses on securities available for sale, net of deferred federal income taxes			(19,000)			(19,000)
Restricted share awards issued		475				475
Recognition of employee share-based compensation, net of deferred federal income taxes		1,384				1,384
Dividends paid and accrued				(13,459)		(13,459)
Acquisition of treasury stock						0
Balance at Mar. 31, 2021	178	211,638	34,527	767,744	(123,834)	890,253
Balance at Dec. 31, 2021	178	216,070	24,579	821,743	(135,397)	927,173
Net income				7,838		7,838
Unrealized losses on securities available for sale, net of deferred federal income taxes			(47,357)			(47,357)
Restricted share awards issued	1	603				604
Recognition of employee share-based compensation, net of deferred federal income taxes		1,479				1,479
Dividends paid and accrued				(13,246)		(13,246)
Acquisition of treasury stock					(14,603)	(14,603)
Balance at Mar. 31, 2022	$ 179	$ 218,152	$ (22,778)	$ 816,335	$ (150,000)	$ 861,888