Consolidated Condensed Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Net sales	$ 117,842	$ 108,508
Cost of sales	68,480	65,186
Gross margin	49,362	43,322
Selling, engineering and administration	31,615	27,307
Operating earnings	17,747	16,015
Interest expense, net	7	31
Other pension and postretirement costs	31	44
Earnings before income taxes	17,709	15,940
Provision for income taxes	3,928	4,086
Net earnings	$ 13,781	$ 11,854
Earnings per share:
Basic	$ 0.47	$ 0.41
Diluted	0.47	0.41
Dividends declared per common share	$ 0.18	$ 0.17
Shares used in computation of earnings per share:
Basic	29,098,490	29,042,158
Impact of dilutive securities	218,098	181,757
Diluted	29,316,588	29,223,915