Guarantees - Activity Related to Product Warranty (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 28, 2014		Jun. 29, 2013		Jun. 28, 2014		Jun. 29, 2013
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance	$ 26,385		$ 16,672		$ 22,908		$ 16,482
Charges to operations	6,800		6,178		12,360		10,346
Utilization	(2,370)		(2,055)		(5,612)		(4,138)
Change in estimate	(2,867)	[1]	(1,094)	[1]	(1,708)	[1]	(2,989)	[1]
Balance at the end of the period	$ 27,948		$ 19,701		$ 27,948		$ 19,701

[1] The Company records hardware warranty liabilities based on the latest quality and cost information available as of that date. The changes in estimate shown here are due to changes in overall actual failure rates and the resulting impact of these changes on the Company’s estimate of expected future returns, as well as changes in the estimated cost and the mix of new versus used units related to replacement of failed units.