Condensed Consolidated Statements of Net Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Net sales	$ 459,183	$ 313,355	$ 876,996	$ 598,797
Cost of sales	290,196	180,747	558,386	352,539
Gross profit	168,987	132,608	318,610	246,258
Selling, general, and administrative expenses	73,244	53,438	150,758	100,139
Research and development expenses	22,748	12,729	45,288	24,881
Amortization of intangibles	13,373	6,171	25,371	12,115
Total operating expenses	109,365	72,338	221,417	137,135
Operating income	59,622	60,270	97,193	109,123
Interest expense	5,782	3,281	11,205	6,401
Foreign exchange loss (gain)	3,200	(558)	(7,354)	(2,115)
Other (income) expense, net	(1,678)	190	(3,621)	52
Income before income taxes	52,318	57,357	96,963	104,785
Income taxes	9,992	8,719	18,609	17,255
Net income	$ 42,326	$ 48,638	$ 78,354	$ 87,530
Income per share:
Basic (in dollars per share)	$ 1.69	$ 2.13	$ 3.18	$ 3.84
Diluted (in dollars per share)	$ 1.67	$ 2.11	$ 3.12	$ 3.80
Weighted-average shares and equivalent shares outstanding:
Basic (in shares)	25,004	22,822	24,671	22,785
Diluted (in shares)	25,401	23,023	25,086	23,005