Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]
Balance at Dec. 29, 2017	$ 107,275	$ 56	$ 288,297	$ (134,054)	$ (38,515)	$ (8,509)
Balance, Shares at Dec. 29, 2017		55,745		(26,945)
Issuance of common stock	(3,003)	$ 1	(3,004)
Issuance of common stock, Shares		721
Treasury stock purchased	(964)		1,346	$ (2,310)
Treasury stock purchased, Shares				(126)
Amortization of restricted stock units and common stock subject to vesting requirements	3,557		3,557
Net income	7,367				7,367
Foreign currency translation	1,152					1,152
Balance at Mar. 30, 2018	115,384	$ 57	290,196	$ (136,364)	(31,148)	(7,357)
Ending Balance, Shares at Mar. 30, 2018		56,466		(27,071)
Balance at Dec. 28, 2018	123,590	$ 57	296,955	$ (136,604)	(25,424)	(11,394)
Balance, Shares at Dec. 28, 2018		56,615		(27,086)
Issuance of common stock	(2,372)	$ 1	(2,373)
Issuance of common stock, Shares		394
Treasury stock purchased	(1,616)			$ (1,616)
Treasury stock purchased, Shares				(102)
Amortization of restricted stock units and common stock subject to vesting requirements	2,394		2,394
Dividends declared	(5,400)
Net income	7,094				7,094
Foreign currency translation	657					657
Balance at Mar. 29, 2019	$ 129,747	$ 58	$ 296,976	$ (138,220)	$ (18,330)	$ (10,737)
Ending Balance, Shares at Mar. 29, 2019		57,009		(27,188)