Guarantees - Activity Related to Product Warranty (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 28, 2013		Sep. 29, 2012		Sep. 28, 2013		Sep. 29, 2012
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance	$ 19,701		$ 13,702		$ 16,482		$ 12,865
Charges to operations	5,220		4,241		16,646		10,065
Utilization	(2,645)		(1,684)		(6,783)		(5,488)
Change in estimate	886	[1]	(960)	[1]	(3,183)	[1]	(2,143)	[1]
Balance at the end of the period	$ 23,162		$ 15,299		$ 23,162		$ 15,299

[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 impact of these changes on the Company’s estimate of expected future returns and changes in the estimated cost of replacing failed units using either repaired or new units.