Condensed Consolidated Statements of Net Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Income Statement [Abstract]
Net sales	$ 405,500	$ 417,813
Cost of sales	250,272	268,190
Gross profit	155,228	149,623
Selling, general, and administrative expenses	62,955	77,514
Research and development expenses	21,409	22,540
Amortization of intangibles	10,191	11,998
Total operating expenses	94,555	112,052
Operating income	60,673	37,571
Interest expense	5,686	5,423
Foreign exchange loss (gain)	4,243	(10,555)
Other expense (income), net	4,305	(1,943)
Income before income taxes	46,439	44,646
Income taxes	9,450	8,617
Net income	$ 36,989	$ 36,029
Income per share:
Basic (in dollars per share)	$ 1.50	$ 1.48
Diluted (in dollars per share)	$ 1.48	$ 1.45
Weighted-average shares and equivalent shares outstanding:
Basic (in shares)	24,717	24,339
Diluted (in shares)	25,009	24,775