CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss	KSOP-Owned Shares
Beginning balance at Dec. 31, 2016	$ 110,253	$ 9,616	$ 101,736	$ 57,160	$ (20,111)	$ (6,487)	$ (31,661)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	14,439			14,439
Other comprehensive income (loss)	360					360
Terminated KSOP put option	34,300						34,300
Exercise of stock options	84	5	55		24
Sale/Issuance of common stock	55,755	2,300	53,455
Stock based compensation	355		355
Net change in fair value of KSOP shares	(2,639)						$ (2,639)
Dividends: Common Stock	(5,562)			(5,562)
Ending balance at Dec. 31, 2017	207,345	11,921	155,601	66,037	(20,087)	(6,127)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	20,596			20,596
Other comprehensive income (loss)	(2,549)					(2,549)
Reclassification of certain tax effects from accumulated other comprehensive income				486		(486)
Terminated KSOP put option	0
Exercise of stock options	327	14	313
Purchase of treasury stock	(4,265)				(4,265)
Sale/Issuance of common stock	29,568	900	28,668
Stock based compensation	592		592
Net change in fair value of KSOP shares	0
Dividends: Common Stock	(7,031)			(7,031)
Ending balance at Dec. 31, 2018	244,583	12,835	185,174	80,088	(24,352)	(9,162)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	26,279			26,279
Other comprehensive income (loss)	7,369					7,369
Terminated KSOP put option	0
Exercise of stock options	925	39	886
Purchase of treasury stock	(10,140)				(10,140)
Restricted stock grants		31	(31)
Stock based compensation	663		663
Net change in fair value of KSOP shares	0
Dividends: Common Stock	(8,128)			(8,128)
Ending balance at Dec. 31, 2019	$ 261,551	$ 12,905	$ 186,692	$ 98,239	$ (34,492)	$ (1,793)