Consolidated Statements of Stockholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income
Beginning Balance Value at Dec. 31, 2011	$ 209,992	$ 23	$ 236,735	$ (28,315)	$ 1,549
Beginning Balance Shares at Dec. 31, 2011		23,182,771
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	4,465			4,465
Employee benefit plan adjustment	(11)				(11)
Foreign currency translation adjustments	(264)				(264)
Unrealized gain (loss) on investments, net of tax	(2)				(2)
Issuance of common stock under stock-based compensation plans	4,205	0	4,205
Issuance of common stock under stock-based compensation plans, Shares		655,424
Stock-based compensation expense	5,890		5,890
Repurchases and retirement of common stock	(8,504)		(8,504)
Repurchases and retirement of common stock, Shares	(587,766)	(587,766)
Ending Balance Value at Dec. 29, 2012	215,771	23	238,326	(23,850)	1,272
Ending Balance Shares at Dec. 29, 2012		23,250,429
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(14,146)			(14,146)
Employee benefit plan adjustment	151				151
Foreign currency translation adjustments	(818)				(818)
Unrealized gain (loss) on investments, net of tax	7				7
Issuance of common stock under stock-based compensation plans	3,734	1	3,733
Issuance of common stock under stock-based compensation plans, Shares		619,617
Stock-based compensation expense	7,674		7,674
Repurchases and retirement of common stock	(5,000)		(5,000)
Repurchases and retirement of common stock, Shares	(332,771)	(332,771)
Ending Balance Value at Dec. 28, 2013	207,373	24	244,733	(37,996)	612
Ending Balance Shares at Dec. 28, 2013	23,537,275	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 (loss) on investments, net of tax	(36)				(36)
Issuance of common stock under stock-based compensation plans	5,255	0	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	(5,344)		(5,344)
Repurchases and retirement of common stock, 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	23,813,729