Condensed Consolidated Statements of Comprehensive Loss (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
Net loss	$ (6,669)	$ (11,204)	$ (33,453)	$ (44,022)
Unrealized (loss) gain on marketable securities		(55)	81	1,305
Foreign currency translation adjustment				3
Net recognized gain on marketable securities previously included in Accumulated other comprehensive income		(25)	(1,728)	(1,476)
Comprehensive loss	$ (6,669)	$ (11,284)	$ (35,100)	$ (44,190)