Condensed Consolidated Statements of Stockholders’ Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative catch-up adjustment for ASC 842 | Accounting Standards Update 2014-09	$ (1,506)			$ (1,506)
Beginning balance, shares at Jan. 02, 2018		43,550,329	2,423,871
Beginning balance at Jan. 02, 2018	$ 35,861	$ 436	$ (35,000)	171,613	$ (101,188)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Proceeds from exercise of stock options, warrants and employee stock purchase plan (in shares)	35,000	8,983
Proceeds from exercise of stock options, warrants and employee stock purchase plan		$ 0		35
Stock-based compensation expense				592
Net loss	$ (3,575)				(3,575)
Ending balance at Apr. 03, 2018	31,407	$ 436	$ (35,000)	172,240	(106,269)
Ending balance, shares at Apr. 03, 2018		43,559,312	2,423,871
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative catch-up adjustment for ASC 842 | Accounting Standards Update 2016-02	(5,992)			(5,992)
Beginning balance, shares at Jan. 01, 2019		46,353,309	2,423,871
Beginning balance at Jan. 01, 2019	$ 52,681	$ 464	$ (35,000)	198,352	(111,135)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Proceeds from exercise of stock options, warrants and employee stock purchase plan (in shares)	21,000	17,642
Proceeds from exercise of stock options, warrants and employee stock purchase plan		$ 0		21
Stock-based compensation expense	$ 737			737
Net loss	(1,851)				(1,851)
Ending balance at Apr. 02, 2019	$ 45,596	$ 464	$ (35,000)	$ 199,110	$ (118,978)
Ending balance, shares at Apr. 02, 2019		46,370,951	2,423,871