CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Oct. 01, 2022	Sep. 30, 2023	Oct. 01, 2022
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (1,576)	$ (3,236)	$ (10,345)	$ (13,909)
Other comprehensive income (loss), before tax
Change in unrealized net gain (loss) on available-for-sale investments	101	(225)	323	(560)
Foreign currency translation losses	(15)	(233)	(234)	(485)
Other comprehensive income (loss), before tax	86	(458)	89	(1,045)
Income tax (expense) benefit related to items in other comprehensive loss	0	0	0	0
Other comprehensive income (loss), net of tax	86	(458)	89	(1,045)
Comprehensive loss	$ (1,490)	$ (3,694)	$ (10,256)	$ (14,954)