CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Income Statement [Abstract]
Revenue	$ 162,584	$ 155,468
Cost of revenue	93,844	91,023
Gross profit	68,740	64,445
Operating expenses:
Research and development and engineering	18,682	15,334
Selling, general and administrative	31,653	30,755
Amortization of purchased intangible assets	3,575	3,445
Restructuring, acquisition, and related costs	3,731	1,661
Total operating expenses	57,641	51,195
Operating income	11,099	13,250
Interest income (expense), net	(1,408)	(1,678)
Foreign exchange transaction gains (losses), net	(257)	254
Other income (expense), net	(70)	83
Income before income taxes	9,364	11,909
Income tax provision (benefit)	(1,946)	(38)
Consolidated net income	$ 11,310	$ 11,947
Earnings per common share (Note 4):
Basic	$ 0.32	$ 0.34
Diluted	$ 0.32	$ 0.34
Weighted average common shares outstanding—basic	35,279	35,152
Weighted average common shares outstanding—diluted	35,789	35,561