Computation of Basic and Diluted Net 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				6 Months Ended
	Jun. 27, 2020	Jun. 27, 2020	Jun. 29, 2019	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Numerator:
Net loss	$ (2,780)	$ (2,780)	$ (2,419)	$ (2,419)	$ (4,431)	$ (5,467)
Denominator:
Weighted average shares of common stock (basic)		13,792	13,648		13,789	13,639
Weighted average shares of common stock (diluted)		13,792	13,648		13,789	13,639
Per share data:
Basic net loss per share		$ (0.20)	$ (0.18)		$ (0.32)	$ (0.40)
Diluted net loss per share		$ (0.20)	$ (0.18)		$ (0.32)	$ (0.40)