CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Impact of adoption of ASC 326	Common Stock	Additional Paid-in Capital	Retained Earnings	Retained Earnings Impact of adoption of ASC 326	Treasury Stock	Accumulated Other Comprehensive Income
Beginning balance at Dec. 31, 2019	$ 261,551	$ (3,593)	$ 12,905	$ 186,692	$ 98,239	$ (3,593)	$ (34,492)	$ (1,793)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	7,353				7,353
Other comprehensive income (loss)	10,868							10,868
10% stock dividend	0
Exercise of stock options	72		3	69
Purchase of treasury stock	(13,477)						(13,477)
Stock based compensation	312			312
Dividends: Common Stock	(4,211)				(4,211)
Ending balance at Jun. 30, 2020	258,875		12,908	187,073	97,788		(47,969)	9,075
Beginning balance at Mar. 31, 2020	253,646		12,908	186,916	98,805		(45,309)	326
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	1,075				1,075
Other comprehensive income (loss)	8,749							8,749
Purchase of treasury stock	(2,660)						(2,660)
Stock based compensation	157			157
Dividends: Common Stock	(2,092)				(2,092)
Ending balance at Jun. 30, 2020	258,875		12,908	187,073	97,788		(47,969)	9,075
Beginning balance at Dec. 31, 2020	272,643		12,952	188,032	113,449		(51,419)	9,629
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	21,394				21,394
Other comprehensive income (loss)	(2,450)							(2,450)
10% stock dividend	35,947		1,094	34,853	(35,947)
Exercise of stock options	636		28	608
Stock based compensation	329			329
Dividends: Common Stock	(4,823)				(4,823)
Ending balance at Jun. 30, 2021	287,729		14,074	223,822	94,073		(51,419)	7,179
Beginning balance at Mar. 31, 2021	280,097		14,070	223,550	86,053		(51,419)	7,843
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	10,432				10,432
Other comprehensive income (loss)	(664)							(664)
Exercise of stock options	109		4	105
Stock based compensation	167			167
Dividends: Common Stock	(2,412)				(2,412)
Ending balance at Jun. 30, 2021	$ 287,729		$ 14,074	$ 223,822	$ 94,073		$ (51,419)	$ 7,179