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. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Numerator:
Net loss	$ (3,074)	$ (3,096)	$ (9,957)	$ (7,712)
Denominator:
Weighted average shares of common stock (basic)	11,925	11,569	11,732	11,544
Weighted average shares of common stock (diluted)	11,925	11,569	11,732	11,544
Per share data:
Basic net loss per share	$ (0.26)	$ (0.27)	$ (0.85)	$ (0.67)
Diluted net loss per share	$ (0.26)	$ (0.27)	$ (0.85)	$ (0.67)