Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning Balance, value at Jan. 03, 2015	$ 33,736	$ 108	$ 38,511	$ (4,883)
Beginning Balance, shares at Jan. 03, 2015		9,786,695
Issuance of common stock under stock option plan	$ 1,027	$ 3	1,024
Issuance of common stock under stock option plan, shares	277,733	277,733
Employee stock-based compensation expense	$ 895		895
Release of restricted stock, value	(606)		(606)
Release of restricted stock, shares		144,756
Repurchase of employee share awards	(275)		(275)
Stock repurchase	$ (1,563)		(1,563)
Stock repurchase, shares	(199,776)	(199,776)
Net (loss) income	$ 474			474
Ending Balance, value at Jan. 02, 2016	33,688	$ 111	37,986	(4,409)
Ending Balance, shares at Jan. 02, 2016		10,009,408
Proceeds from issuance of common stock, net of issuance costs, value	14,813	$ 12	14,801
Proceeds from issuance of common stock, net of issuance costs, shares		1,150,000
Issuance of common stock under stock option plan	$ 709	$ 1	708
Issuance of common stock under stock option plan, shares	126,077	126,077
Employee stock-based compensation expense	$ 1,821		1,821
Release of restricted stock, value	(99)		(99)
Release of restricted stock, shares		25,795
Stock repurchase	$ (59)		(59)
Stock repurchase, shares	(6,544)	(6,544)
Net (loss) income	$ (11,713)			(11,713)
Ending Balance, value at Dec. 31, 2016	$ 39,160	$ 124	55,158	(16,122)
Ending Balance, shares at Dec. 31, 2016	11,304,736	11,304,736
Proceeds from issuance of common stock, net of issuance costs, value	$ 2,263	$ 2	2,261
Proceeds from issuance of common stock, net of issuance costs, shares		172,500
Issuance of common stock under stock option plan	$ 377		377
Issuance of common stock under stock option plan, shares	64,380	64,380
Employee stock-based compensation expense	$ 1,922		1,922
Release of restricted stock, value	$ (333)		(333)
Release of restricted stock, shares		54,658
Stock repurchase, shares	0
Net (loss) income	$ (12,867)			(12,867)
Ending Balance, value at Dec. 30, 2017	$ 30,522	$ 126	$ 59,385	$ (28,989)
Ending Balance, shares at Dec. 30, 2017	11,596,274	11,596,274