CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Total	Auction rate securities [Member]	Other Investments [Member]	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Auction rate securities [Member]	Accumulated Other Comprehensive Loss Other Investments [Member]	Accumulated Deficit
Balance at Dec. 31, 2011	$ 387,803			$ 107	$ 876,927	$ (2,195)			$ (487,036)
Balance (in shares) at Dec. 31, 2011				106,976
Stock options exercised	2,553			1	2,552
Stock options exercised (in shares)	582			582
ESPP shares purchased	9,030			1	9,029
ESPP shares issued (in shares)				1,653
Shares withheld for tax obligation (in shares)				(128)
Shares withheld for tax obligation	(882)				(882)
Restricted stock units released (in shares)				3,378
Restricted stock units released				3	(3)
Stock-based compensation	42,995				42,995
Comprehensive loss:
Unrealized gain on available-for-sale investments		(141)	158				(141)	158
Foreign currency translation adjustment	(43)					(43)
Tax effect on items related to available-for-sale investment	(7)					(7)
Net loss	(85,330)								(85,330)
Total comprehensive loss	(85,363)
Balance at Dec. 29, 2012	356,136			112	930,618	(2,228)			(572,366)
Balance (in shares) at Dec. 29, 2012				112,461
Stock options exercised	14,618			2	14,616
Stock options exercised (in shares)	2,217			2,217
ESPP shares purchased	8,559			2	8,557
ESPP shares issued (in shares)				1,656
Shares withheld for tax obligation (in shares)				(223)
Shares withheld for tax obligation	(1,544)				(1,544)
Restricted stock units released (in shares)				3,754
Restricted stock units released				4	(4)
Warrants exercised (in warrants)				22
Stock-based compensation	30,077				30,077
Conversion option related to convertible senior notes, net of allocated costs	43,341				43,341
Comprehensive loss:
Unrealized gain on available-for-sale investments		(166)	(140)				(166)	(140)
Foreign currency translation adjustment	(952)					(952)
Tax effect on items related to available-for-sale investment	0					0
Net loss	(32,119)								(32,119)
Total comprehensive loss	(33,377)
Balance at Dec. 28, 2013	417,810			120	1,025,661	(3,486)			(604,485)
Balance (in shares) at Dec. 28, 2013				119,887
Stock options exercised	13,983			2	13,981
Stock options exercised (in shares)	2,001			2,001
ESPP shares purchased	10,728			1	10,727
ESPP shares issued (in shares)				1,438
Shares withheld for tax obligation (in shares)				(217)
Shares withheld for tax obligation	(1,846)				(1,846)
Restricted stock units released (in shares)				3,051
Restricted stock units released				3	(3)
Stock-based compensation	28,705				28,705
Comprehensive loss:
Unrealized gain on available-for-sale investments			(320)					(320)
Foreign currency translation adjustment	(812)					(812)
Tax effect on items related to available-for-sale investment	0
Net loss	13,659								13,659
Total comprehensive loss	12,527
Balance at Dec. 27, 2014	$ 481,907			$ 126	$ 1,077,225	$ (4,618)			$ (590,826)
Balance (in shares) at Dec. 27, 2014				126,160