Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income
Beginning Balance Value at Dec. 28, 2013	$ 207,373	$ 24	$ 244,733	$ (37,996)	$ 612
Beginning Balance Shares at Dec. 28, 2013		23,537,275
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(31,118)			(31,118)
Employee benefit plan adjustment	(106)				(106)
Foreign currency translation adjustments	(3,239)				(3,239)
Unrealized gain on investments, net of tax	(36)				(36)
Issuance of common stock under stock-based compensation plans	5,255		5,255
Issuance of common stock under stock-based compensation plans, Shares		639,087
Stock-based compensation expense	6,752		6,752
Repurchases and retirement of common stock under share repurchase plans	$ (5,344)		(5,344)
Repurchases and retirement of common stock under share repurchase plans, Shares	(362,633)	(362,633)
Ending Balance Value at Dec. 27, 2014	$ 179,537	$ 24	251,396	(69,114)	(2,769)
Ending Balance Shares at Dec. 27, 2014		23,813,729
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	2,905			2,905
Employee benefit plan adjustment	(76)				(76)
Foreign currency translation adjustments	(2,344)				(2,344)
Unrealized gain on investments, net of tax	(13)				(13)
Issuance of common stock under stock-based compensation plans	2,792		2,792
Issuance of common stock under stock-based compensation plans, Shares		521,607
Stock-based compensation expense	6,248		6,248
Repurchases and retirement of common stock under share repurchase plans	$ (1,721)		(1,721)
Repurchases and retirement of common stock under share repurchase plans, Shares	(111,050)	(111,050)
Ending Balance Value at Dec. 26, 2015	$ 187,328	$ 24	258,715	(66,209)	(5,202)
Ending Balance Shares at Dec. 26, 2015	24,224,286	24,224,286
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 44,035			44,035
Employee benefit plan adjustment	(17)				(17)
Foreign currency translation adjustments	(869)				(869)
Unrealized gain on investments, net of tax	42				42
Issuance of common stock under stock-based compensation plans	6,625	$ 1	6,624
Issuance of common stock under stock-based compensation plans, Shares		846,603
Stock-based compensation expense	7,666		7,666
Excess tax benefit related to stock options	$ (1,036)		(1,036)
Repurchases and retirement of common stock under share repurchase plans, Shares	0
Ending Balance Value at Dec. 31, 2016	$ 243,774	$ 25	$ 271,969	$ (22,174)	$ (6,046)
Ending Balance Shares at Dec. 31, 2016	25,070,889	25,070,889