CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive (Loss) Income
Balance at beginning of the period at Dec. 30, 2017	$ (76,231)	$ 815	$ 219,095	$ (296,184)	$ 43
Balance at beginning of the period (shares) at Dec. 30, 2017		81,535
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	10,031		10,031
Exercise of stock options	53		53
Exercise of stock options (in shares)		11
Dividends	(1,523)			(1,523)
Other comprehensive loss	(59)				(59)
Net income	32,594			32,594
Shares withheld related to net share settlement of stock-based compensation	(57)		(57)
Shares withheld related to net share settlement of stock-based compensation (in shares)		(2)
Repurchase of common stock	(1,967)	$ (4)	(1,963)
Repurchase of common stock (shares)		(397)
Balance at end of the period at Sep. 29, 2018	(37,159)	$ 811	227,159	(265,113)	(16)
Balance at end of the period (shares) at Sep. 29, 2018		81,147
Balance at beginning of the period at Jun. 30, 2018	$ (56,801)	$ 811	224,236	(281,834)	(14)
Balance at beginning of the period (shares) at Jun. 30, 2018	81,147
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 2,923		2,923
Dividends	(309)			(309)
Other comprehensive loss	(2)				(2)
Net income	17,030			17,030
Balance at end of the period at Sep. 29, 2018	(37,159)	$ 811	227,159	(265,113)	(16)
Balance at end of the period (shares) at Sep. 29, 2018		81,147
Balance at beginning of the period at Dec. 29, 2018	28,971	$ 842	268,327	(240,104)	(94)
Balance at beginning of the period (shares) at Dec. 29, 2018		84,196
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	10,399		10,399
Exercise of stock options	2,708	$ 16	2,692
Exercise of stock options (in shares)		1,579
Dividends	(375)			(375)
Other comprehensive loss	(35)				(35)
Net income	45,692			45,692
Adoption of new accounting standard	500			500
Balance at end of the period at Sep. 28, 2019	87,860	$ 858	281,418	(194,287)	(129)
Balance at end of the period (shares) at Sep. 28, 2019		85,775
Balance at beginning of the period at Jun. 29, 2019	63,952	$ 848	278,671	(215,533)	(34)
Balance at beginning of the period (shares) at Jun. 29, 2019		84,820
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	2,113		2,113
Exercise of stock options	644	$ 10	634
Exercise of stock options (in shares)		955
Dividends	(56)			(56)
Other comprehensive loss	(95)				(95)
Net income	21,302			21,302
Balance at end of the period at Sep. 28, 2019	$ 87,860	$ 858	$ 281,418	$ (194,287)	$ (129)
Balance at end of the period (shares) at Sep. 28, 2019		85,775