Condensed Consolidated Statements of Shareholders' Equity (Deficit) (unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit (Retained Earnings)
Balance at Dec. 30, 2017	$ 89,156	$ 388	$ 0	$ 88,768
Balance (in shares) at Dec. 30, 2017		38,813,000
Net income	20,548	$ 0	0	20,548
Exercise of common stock options	857	$ 1	856	0
Exercise of common stock options (in shares)		68,000
Stock-based compensation	3,084	$ 2	3,082	0
Stock-based compensation (in shares)		211,000
Repurchases of common stock	(77,648)	$ (22)	(3,938)	(73,688)
Repurchases of common stock (in shares)		(2,149,000)
Balance at Mar. 31, 2018	35,997	$ 369	0	35,628
Balance (in shares) at Mar. 31, 2018		36,943,000
Balance at Dec. 29, 2018	$ (109,550)	$ 309	0	(109,859)
Balance (in shares) at Dec. 29, 2018	30,868,000	30,868,000
Net income	$ 25,418	$ 0	0	25,418
Exercise of common stock options	2,836	$ 2	2,834	0
Exercise of common stock options (in shares)		151,000
Stock-based compensation	3,638	$ 3	3,635	0
Stock-based compensation (in shares)		364,000
Repurchases of common stock	(46,982)	$ (12)	(6,469)	(40,501)
Repurchases of common stock (in shares)		(1,170,000)
Balance at Mar. 30, 2019	$ (124,640)	$ 302	$ 0	$ (124,942)
Balance (in shares) at Mar. 30, 2019	30,213,000	30,213,000