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		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
Numerator:
Net loss	$ (1,785)	$ (3,074)	$ (7,252)	$ (9,957)
Denominator:
Weighted average shares of common stock (basic)	13,768	11,925	13,682	11,732
Weighted average shares of common stock (diluted)	13,768	11,925	13,682	11,732
Per share data:
Basic net loss per share	$ (0.13)	$ (0.26)	$ (0.53)	$ (0.85)
Diluted net loss per share	$ (0.13)	$ (0.26)	$ (0.53)	$ (0.85)