Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 29, 2020	Mar. 31, 2019
Income Statement [Abstract]
Revenue	$ 167,235	$ 173,484
Cost of revenue	41,200	46,284
Gross margin	126,035	127,200
Research, development, and engineering expenses	35,946	30,242
Selling, general, and administrative expenses	69,138	66,811
Operating income	20,951	30,147
Foreign currency gain (loss)	(3,003)	(248)
Investment income	5,229	4,905
Other income (expense)	(183)	927
Income before income tax expense	22,994	35,731
Income tax expense	2,517	2,627
Net Income	$ 20,477	$ 33,104
Net income per weighted-average common and common-equivalent share:
Basic (usd per share)	$ 0.12	$ 0.19
Diluted (usd per share)	$ 0.12	$ 0.19
Weighted-average common and common-equivalent shares outstanding:
Basic (shares)	172,408	171,098
Diluted (shares)	175,602	175,607
Cash dividends per common share (usd per share)	$ 0.055	$ 0.050