Condensed Consolidated Statements of Net Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
Income Statement [Abstract]
Net sales	$ 361,971	$ 439,191	$ 1,165,350	$ 1,316,187
Cost of sales	231,025	259,597	737,368	817,983
Gross profit	130,946	179,594	427,982	498,204
Selling, general, and administrative expenses	54,224	69,782	174,845	220,540
Research and development expenses	19,728	20,454	62,595	65,742
Amortization of intangibles	9,827	13,130	30,068	38,501
Total operating expenses	83,779	103,366	267,508	324,783
Operating income	47,167	76,228	160,474	173,421
Interest expense	5,559	5,775	16,834	16,980
Foreign exchange loss (gain)	4,968	982	5,636	(6,372)
Other (income) expense, net	(4,764)	1,259	(3,406)	(2,362)
Income before income taxes	41,404	68,212	141,410	165,175
Income taxes	5,757	14,666	24,982	33,275
Net income	$ 35,647	$ 53,546	$ 116,428	$ 131,900
Income per share:
Basic (in dollars per share)	$ 1.46	$ 2.13	$ 4.72	$ 5.31
Diluted (in dollars per share)	$ 1.44	$ 2.10	$ 4.68	$ 5.23
Weighted-average shares and equivalent shares outstanding:
Basic (in shares)	24,482	25,109	24,646	24,817
Diluted (in shares)	24,684	25,471	24,894	25,212