Changes in Stockholders' Equity and Accumulated other Comprehensive loss (in thousands) (Details) (USD $) Share data in Millions, unless otherwise specified	0 Months Ended	3 Months Ended		9 Months Ended
	Feb. 24, 2012	Sep. 29, 2012	Oct. 01, 2011	Sep. 29, 2012	Oct. 01, 2011
Balance, December 31, 2011				$ 393,561,000
Net loss for the nine months ended September 29, 2012		(2,175,000)	13,337,000	(22,431,000)	37,287,000
Unrealized loss related to marketable securities, net		39,000	(1,000)	17,000	(8,000)
Recognized gain on redemption of marketable securities, previously unrealilzed				(78,000)
Translation adjustments		(15,000)	(6,000)	244,000	(61,000)
Common stock issued in connection with the exercise of stock options, ESPP and vested RSUs (net of taxes)				2,246,000
Stock repurchase				(12,360,000)
Retirement of treasury stock				0
Stock-based compensation expense related to stock options, ESPP and RSUs		2,075,000	1,687,000	5,753,000	4,768,000
Balance, September 29, 2012		366,952,000		366,952,000
Stock repurchase program, authorized amount	20,000,000
Shares repurchased		1.4		2.7
Shares repurchased, value		5,400,000		12,400,000
Common stock
Balance, December 31, 2011				1,177,000
Common stock issued in connection with the exercise of stock options, ESPP and vested RSUs (net of taxes)				11,000
Retirement of treasury stock				(27,000)
Balance, September 29, 2012		1,161,000		1,161,000
Additional paid-in capital
Balance, December 31, 2011				627,637,000
Common stock issued in connection with the exercise of stock options, ESPP and vested RSUs (net of taxes)				2,235,000
Retirement of treasury stock				(12,333,000)
Stock-based compensation expense related to stock options, ESPP and RSUs				5,753,000
Balance, September 29, 2012		623,292,000		623,292,000
Treasury stock
Balance, December 31, 2011				0
Stock repurchase				(12,360,000)
Retirement of treasury stock				12,360,000
Balance, September 29, 2012		0		0
Accumulated deficit
Balance, December 31, 2011				(234,908,000)
Net loss for the nine months ended September 29, 2012				(22,431,000)
Balance, September 29, 2012		(257,339,000)		(257,339,000)
Accumulated other comprehensive loss
Balance, December 31, 2011				(345,000)
Unrealized loss related to marketable securities, net				17,000
Recognized gain on redemption of marketable securities, previously unrealilzed				(78,000)
Translation adjustments				244,000
Balance, September 29, 2012		$ (162,000)		$ (162,000)