CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2021	Jul. 03, 2020	Jul. 02, 2021	Jul. 03, 2020
Income Statement [Abstract]
Revenue	$ 167,523	$ 144,728	$ 330,107	$ 300,196
Cost of revenue	95,117	86,026	188,961	177,049
Gross profit	72,406	58,702	141,146	123,147
Operating expenses:
Research and development and engineering	16,954	14,440	35,636	29,774
Selling, general and administrative	31,240	24,908	62,893	55,663
Amortization of purchased intangible assets	3,586	3,410	7,161	6,855
Restructuring, acquisition, and related costs	4,634	2,243	8,365	3,904
Total operating expenses	56,414	45,001	114,055	96,196
Operating income	15,992	13,701	27,091	26,951
Interest income (expense), net	(1,378)	(1,701)	(2,786)	(3,379)
Foreign exchange transaction gains (losses), net	(76)	(282)	(333)	(28)
Other income (expense), net	(97)	(22)	(167)	61
Income before income taxes	14,441	11,696	23,805	23,605
Income tax provision (benefit)	2,777	36	831	(2)
Consolidated net income	$ 11,664	$ 11,660	$ 22,974	$ 23,607
Earnings per common share (Note 4):
Basic	$ 0.33	$ 0.33	$ 0.65	$ 0.67
Diluted	$ 0.33	$ 0.33	$ 0.64	$ 0.66
Weighted average common shares outstanding—basic	35,374	35,137	35,326	35,145
Weighted average common shares outstanding—diluted	35,763	35,579	35,775	35,570