Consolidated Condensed Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Net sales	$ 122,869	$ 91,119	$ 240,711	$ 199,627
Cost of sales	72,767	55,269	141,247	120,455
Gross margin	50,102	35,850	99,464	79,172
Selling, engineering and administration	31,427	23,186	63,042	50,493
Operating earnings	18,675	12,664	36,422	28,679
Interest expense, net	7	32	14	63
Other pension and postretirement costs	29	44	60	88
Earnings before income taxes	18,639	12,588	36,348	28,528
Provision for income taxes	4,667	3,054	8,595	7,140
Net earnings	$ 13,972	$ 9,534	$ 27,753	$ 21,388
Earnings per share:
Basic	$ 0.48	$ 0.33	$ 0.95	$ 0.74
Diluted	0.48	0.33	0.95	0.73
Dividends declared per common share	$ 0.18	$ 0.17	$ 0.36	$ 0.34
Shares used in computation of earnings per share:
Basic	29,114,346	29,047,297	29,105,429	29,046,277
Impact of dilutive securities	197,828	218,422	207,963	200,090
Diluted	29,312,174	29,265,719	29,313,392	29,246,367