CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2021	Oct. 02, 2020	Oct. 01, 2021	Oct. 02, 2020
Income Statement [Abstract]
Revenue	$ 177,726	$ 142,929	$ 507,833	$ 443,125
Cost of revenue	101,428	83,824	290,389	260,873
Gross profit	76,298	59,105	217,444	182,252
Operating expenses:
Research and development and engineering	17,468	15,231	53,104	45,005
Selling, general and administrative	31,296	26,788	94,189	82,451
Amortization of purchased intangible assets	4,139	3,533	11,300	10,388
Restructuring, acquisition and related costs	8,120	1,687	16,485	5,591
Total operating expenses	61,023	47,239	175,078	143,435
Operating income	15,275	11,866	42,366	38,817
Interest income (expense), net	(1,710)	(1,698)	(4,496)	(5,077)
Foreign exchange transaction gains (losses), net	34	(136)	(299)	(164)
Other income (expense), net	(71)	(14)	(238)	47
Income before income taxes	13,528	10,018	37,333	33,623
Income tax provision (benefit)	(75)	1,760	756	1,758
Consolidated net income	$ 13,603	$ 8,258	$ 36,577	$ 31,865
Earnings per common share (Note 5):
Basic	$ 0.38	$ 0.23	$ 1.03	$ 0.91
Diluted	$ 0.38	$ 0.23	$ 1.02	$ 0.89
Weighted average common shares outstanding—basic	35,447	35,142	35,366	35,144
Weighted average common shares outstanding—diluted	35,764	35,688	35,771	35,609