Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Net sales	$ 364,304	$ 309,932	$ 974,048	$ 874,029
Cost of sales	191,061	172,288	521,339	491,952
Gross profit	173,243	137,644	452,709	382,077
Operating expenses:
Research and development and other engineering	12,287	11,972	37,860	35,287
Selling	29,396	27,672	84,757	84,471
General and administrative	40,289	37,047	117,396	117,941
Total operating expenses	81,972	76,691	240,013	237,699
Net gain on disposal of assets	(72)	(14)	(209)	(265)
Income from operations	91,343	60,967	212,905	144,643
Interest expense, net and other	(518)	(1,778)	(3,202)	(2,394)
Income before taxes	90,825	59,189	209,703	142,249
Provision for income taxes	23,768	15,503	52,341	36,324
Net income	67,057	43,686	157,362	105,925
Translation adjustment, net of tax	6,238	5,797	3,170	5,825
Unamortized pension adjustments	28	(362)	88	(462)
Comprehensive net income	$ 73,323	$ 49,121	$ 160,620	$ 111,288
Earnings per common share:
Basic	$ 1.54	$ 0.98	$ 3.60	$ 2.37
Diluted	$ 1.54	$ 0.97	$ 3.59	$ 2.35
Number of shares outstanding
Basic	43,474	44,477	43,683	44,673
Diluted	43,683	44,814	43,873	44,995
Cash dividends declared per common share (in dollars per share)	$ 0.23	$ 0.23	$ 0.69	$ 0.68