Consolidated Condensed Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Net sales	$ 103,542	$ 113,648	$ 208,423	$ 218,689
Cost of sales	63,266	72,144	127,690	140,437
Gross margin	40,276	41,504	80,733	78,252
Selling, engineering and administration	25,243	25,153	51,373	51,927
Operating earnings	15,033	16,351	29,360	26,325
Interest expense, net	85	409	214	699
Other pension and postretirement costs	35	8,031	82	8,012
Earnings before income taxes	14,913	7,911	29,064	17,614
Provision for income taxes	3,555	1,757	6,882	3,914
Net earnings	$ 11,358	$ 6,154	$ 22,182	$ 13,700
Earnings per share:
Basic	$ 0.39	$ 0.21	$ 0.76	$ 0.47
Diluted	0.39	0.21	0.76	0.47
Dividends declared per common share	$ 0.15	$ 0.13	$ 0.30	$ 0.26
Shares used in computation of earnings per share:
Basic	29,027,887	28,963,373	29,024,543	28,965,735
Impact of dilutive securities	183,646	170,070	200,009	193,665
Diluted	29,211,533	29,133,443	29,224,552	29,159,400