Changes in Stockholders' Equity and Accumulated Other Comprehensive Loss (Details) (USD $)	3 Months Ended		6 Months Ended		1 Months Ended	12 Months Ended	0 Months Ended	6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013	Feb. 27, 2013 Share Repurchase Program approved on Feb 27, 2013	Dec. 28, 2013 Share Repurchase Program approved on Feb 27, 2013	Mar. 03, 2014 Share Repurchase Program approved on Feb 27, 2014	Jun. 28, 2014 Common stock	Jun. 28, 2014 Paid-in capital	Jun. 28, 2014 Accumulated deficit	Jun. 28, 2014 Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			$ 385,680,000					$ 1,157,000	$ 626,861,000	$ (242,193,000)	$ (145,000)
Net Income for the period	11,771,000	5,040,000	23,755,000	6,930,000						23,755,000
Unrealized loss related to marketable securities, net			(70,000)								(70,000)
Realized gain on sale of auction rate securities, previously unrealized, net of tax			(1,147,000)								(1,147,000)
Recognized loss on redemption of marketable securities, previously unrealized			99,000								99,000
Translation adjustments	914,000	(265,000)	738,000	(430,000)							738,000
Common stock issued in connection with the exercise of stock options, ESPP and vested RSUs (net of taxes)			7,085,000					27,000	7,058,000
Stock-based compensation expense related to stock options, ESPP and RSUs			6,410,000						6,410,000
Ending balance	422,550,000		422,550,000					1,184,000	640,329,000	(218,438,000)	(525,000)
Stock repurchase program, authorized amount					20,000,000.0		20,000,000.0
Shares repurchased (in shares)	0		0			800,000
Shares repurchased						$ 3,700,000