Condensed Consolidated Statements of Comprehensive Loss (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013
Statement of Comprehensive Income [Abstract]
Net loss	$ (5,964)	$ (448)	$ (15,957)	$ (1,656)
Foreign currency translation adjustments	(1)	10	(4)	11
Unrealized gain (loss) on marketable securities	14	(8)	14	0
Comprehensive loss	$ (5,951)	$ (446)	$ (15,947)	$ (1,645)