Condensed Consolidated Statements of Shareholders' (Deficit) (unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance (in shares) at Dec. 29, 2018		30,868,000
Beginning balance at Dec. 29, 2018	$ (109,550)	$ 309	$ 0	$ (109,859)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	25,418			25,418
Exercise of common stock options (in shares)		151,000
Exercise of common stock options	2,836	$ 2	2,834
Stock-based compensation (in shares)		364,000
Stock-based compensation	3,638	$ 3	3,635
Repurchases of common stock (in shares)		(1,170,000)
Repurchases of common stock	(46,982)	$ (12)	(6,469)	(40,501)
Ending balance (in shares) at Mar. 30, 2019		30,213,000
Ending balance at Mar. 30, 2019	$ (124,640)	$ 302	0	(124,942)
Beginning balance (in shares) at Dec. 28, 2019	27,961,000	27,961,000
Beginning balance at Dec. 28, 2019	$ (159,431)	$ 280	0	(159,711)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	39,140			39,140
Exercise of common stock options (in shares)		167,000
Exercise of common stock options	3,283	$ 1	3,282
Stock-based compensation (in shares)		396,000
Stock-based compensation	2,051	$ 4	2,047
Repurchases of common stock (in shares)		(888,000)
Repurchases of common stock	$ (40,952)	$ (9)	(5,329)	(35,614)
Ending balance (in shares) at Mar. 28, 2020	27,636,000	27,636,000
Ending balance at Mar. 28, 2020	$ (155,909)	$ 276	$ 0	$ (156,185)