CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balance at Dec. 28, 2018	$ 132,426	$ 442	$ 289,584	$ (1,320)	$ (156,280)
Balance (in shares) at Dec. 28, 2018		44,195
Net income (loss)	1,367				1,367
Impact of the adoption standard | Lease Accounting Standard	113				113
Impact of the adoption standard | Nonemployee Share-Based Payment Standard			(315)		315
Other comprehensive income (loss)	(23)			(23)
Common stock issued upon exercise of options	623		623
Common stock issued upon exercise of options (in shares)		74
Stock-based compensation	2,830		2,830
Vested restricted stock	2	$ 2
Vested restricted stock (in shares)		178
Balance at Mar. 29, 2019	137,338	$ 444	292,722	(1,343)	(154,485)
Balance (in shares) at Mar. 29, 2019		44,447
Balance at Jan. 03, 2020	159,884	$ 448	304,288	(3,048)	(141,804)
Balance (in shares) at Jan. 03, 2020		44,822
Net income (loss)	(134)				(134)
Other comprehensive income (loss)	22			22
Common stock issued upon exercise of options	$ 2,004	$ 2	2,002
Common stock issued upon exercise of options (in shares)	196	196
Stock-based compensation	$ 3,190		3,190
Vested restricted stock	1	$ 1
Vested restricted stock (in shares)		87
Balance at Apr. 03, 2020	$ 164,967	$ 451	$ 309,480	$ (3,026)	$ (141,938)
Balance (in shares) at Apr. 03, 2020		45,105