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			6 Months Ended
	Jul. 03, 2021	Jun. 27, 2020	Jun. 27, 2020	Jul. 03, 2021	Jul. 03, 2021	Jun. 27, 2020	Jun. 27, 2020
Numerator:
Net Income (loss)	$ 1,393	$ (2,780)	$ (2,780)	$ (617)	$ (617)	$ (4,431)	$ (4,431)
Denominator:
Weighted average shares of common stock (basic)	15,647	13,792		14,996	14,996	13,789	13,789
Effect of dilutive stock options	427
Weighted average shares of common stock (diluted)	16,307	13,792		14,996	14,996	13,789	13,789
Per share data:
Basic net loss per share	$ 0.09	$ (0.20)		$ (0.04)	$ (0.04)	$ (0.32)	$ (0.32)
Diluted net loss per share	$ 0.09	$ (0.20)		$ (0.04)	$ (0.04)	$ (0.32)	$ (0.32)
Restricted Stock Units (RSUs)
Denominator:
Effect of dilutive stock options	233