Consolidated Condensed Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Net sales	$ 128,738	$ 113,587	$ 369,449	$ 313,214
Cost of sales	77,554	68,564	218,801	189,019
Gross margin	51,184	45,023	150,648	124,195
Selling, engineering and administration	31,744	25,509	94,786	76,001
Operating earnings	19,440	19,514	55,862	48,194
Interest expense (income), net	14	(46)	28	18
Other pension and postretirement costs	30	21	90	109
Earnings before income taxes	19,396	19,539	55,744	48,067
Provision for income taxes	3,541	4,678	12,136	11,818
Net earnings	$ 15,855	$ 14,861	$ 43,608	$ 36,249
Earnings per share:
Basic	$ 0.54	$ 0.51	$ 1.50	$ 1.25
Diluted	0.54	0.51	1.49	1.24
Dividends declared per common share	$ 0.20	$ 0.18	$ 0.56	$ 0.52
Shares used in computation of earnings per share:
Basic	29,157,628	29,048,683	29,124,491	29,049,675
Impact of dilutive securities	184,204	171,814	200,043	169,862
Diluted	29,341,832	29,220,497	29,324,534	29,219,537