Computation of Basic and Diluted Net Income (Loss) Per Common Share - Reconciliation of Numerator and Denominator of Basic and Diluted Net Loss Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 02, 2021	Sep. 26, 2020	Oct. 02, 2021	Sep. 26, 2020
Numerator:
Net loss	$ (2,165)	$ (1,719)	$ (2,782)	$ (6,150)
Denominator:
Weighted average shares of common stock (basic)	15,824	13,893	15,272	13,824
Weighted average shares of common stock (diluted)	15,824	13,893	15,272	13,824
Per share data:
Basic net loss per share	$ (0.14)	$ (0.12)	$ (0.18)	$ (0.44)
Diluted net loss per share	$ (0.14)	$ (0.12)	$ (0.18)	$ (0.44)