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	6,278				6,278
Other comprehensive income (loss)	2,119							2,119
10% stock dividend	0
Exercise of stock options	72		3	69
Purchase of treasury stock	(10,817)						(10,817)
Stock based compensation	155			155
Dividends: Common Stock	(2,119)				(2,119)
Ending balance at Mar. 31, 2020	253,646		12,908	186,916	98,805		(45,309)	326
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	10,962				10,962
Other comprehensive income (loss)	(1,786)							(1,786)
10% stock dividend	35,947		1,094	34,853	(35,947)
Exercise of stock options	527		24	503
Stock based compensation	162			162
Dividends: Common Stock	(2,411)				(2,411)
Ending balance at Mar. 31, 2021	$ 280,097		$ 14,070	$ 223,550	$ 86,053		$ (51,419)	$ 7,843