Consolidated Statements of Net Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Jul. 02, 2016
Net sales	$ 313,355	$ 271,912	$ 598,797	$ 491,310
Cost of sales	180,747	174,046	352,539	306,289
Gross profit	132,608	97,866	246,258	185,021
Selling, general, and administrative expenses	53,438	51,092	100,139	93,458
Research and development expenses	12,729	11,916	24,881	20,481
Amortization of intangibles	6,171	5,156	12,115	8,952
Total operating expenses	72,338	68,164	137,135	122,891
Operating income	60,270	29,702	109,123	62,130
Interest expense	3,281	1,670	6,401	3,715
Foreign exchange gain	(558)	(6,237)	(2,115)	(2,414)
Other expense (income), net	190	255	52	(262)
Income before income taxes	57,357	34,014	104,785	61,091
Income taxes	8,719	6,862	17,255	14,650
Net income	$ 48,638	$ 27,152	$ 87,530	$ 46,441
Income per share:
Basic (in dollars per share)	$ 2.13	$ 1.21	$ 3.84	$ 2.07
Diluted (in dollars per share)	$ 2.11	$ 1.20	$ 3.80	$ 2.05
Weighted-average shares and equivalent shares outstanding:
Basic (in shares)	22,822	22,528	22,785	22,483
Diluted (in shares)	23,023	22,674	23,005	22,647