Consolidated Condensed Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Net sales	$ 108,646	$ 110,630	$ 317,069	$ 329,319
Cost of sales	66,976	66,684	194,666	207,121
Gross margin	41,670	43,946	122,403	122,198
Selling, engineering and administration	25,225	28,212	76,598	80,139
Operating earnings	16,445	15,734	45,805	42,059
Interest expense, net	66	295	280	994
Other pension and postretirement costs	41	11,787	123	19,799
Earnings before income taxes	16,338	3,652	45,402	21,266
Provision for income taxes	3,617	801	10,499	4,715
Net earnings	$ 12,721	$ 2,851	$ 34,903	$ 16,551
Earnings per share:
Basic	$ 0.44	$ 0.10	$ 1.20	$ 0.57
Diluted	0.44	0.10	1.19	0.57
Dividends declared per common share	$ 0.17	$ 0.15	$ 0.47	$ 0.41
Shares used in computation of earnings per share:
Basic	29,013,573	28,989,205	29,022,080	28,983,115
Impact of dilutive securities	179,765	207,955	193,112	198,428
Diluted	29,193,338	29,197,160	29,215,192	29,181,543