Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Apr. 03, 2021	Mar. 28, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (2,010)	$ (1,651)
Foreign currency translation adjustments	38	2
Comprehensive loss	$ (1,972)	$ (1,649)