Commitments and Contingencies - Product Warranty Activities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
Product warranty activities [Roll Forward]
Balance at beginning of period	$ 10,638	$ 12,323	$ 10,856	$ 11,762
Warranty charged to cost of revenue	839	992	3,364	3,774
Utilization of warranty	(702)	(1,955)	(3,445)	(4,176)
Balance at end of period	$ 10,775	$ 11,360	$ 10,775	$ 11,360