Consolidated Condensed Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock at $1 par value	[1]	Capital in excess of par value	Reinvested earnings	Accumulated other comprehensive income (loss)	Employee benefit stock	Treasury stock (at cost)
Balance at beginning of period at Dec. 31, 2018	$ 303,503	$ 37,198		$ 38,082	$ 257,313	$ 580	$ (306)	$ (29,364)
Net earnings	10,824				10,824
Pension and postretirement benefits (net of tax effect)	(12)					(12)
Foreign currency translation	(257)					(257)
Cash dividends	(4,360)				(4,360)
Stock options exercised	471	2		397				72
Stock-based compensation	265			265
Purchase of common stock for treasury stock	(1,873)							(1,873)
Issuance of treasury stock	52			12				40
Balance at end of period at Mar. 31, 2019	308,613	37,200		38,756	263,777	311	(306)	(31,125)
Balance at beginning of period at Dec. 31, 2019	331,068	37,200		41,956	285,879	425	(154)	(34,238)
Net earnings	11,854				11,854
Pension and postretirement benefits (net of tax effect)	1					1
Foreign currency translation	(627)					(627)
Cash dividends	(4,948)				(4,948)
Stock options exercised	478	20		438				20
Stock-based compensation	307			307
Purchase of common stock for treasury stock	(2,467)							(2,467)
Issuance of treasury stock	55			(11)				66
Balance at end of period at Mar. 31, 2020	$ 335,721	$ 37,220		$ 42,690	$ 292,785	$ (201)	$ (154)	$ (36,619)

[1] Each common share of stock equals $1 par value; therefore, the number of common shares is the same as the dollar value.