Acquisitions (Details) (USD $)	9 Months Ended			1 Months Ended		1 Months Ended		1 Months Ended		1 Months Ended	9 Months Ended		1 Months Ended
	Sep. 29, 2012	Sep. 29, 2012 Ember Corporation	Jul. 03, 2012 Ember Corporation	Jul. 31, 2012 Ember Corporation Developed technology	Jul. 03, 2012 Ember Corporation Developed technology	Jul. 31, 2012 Ember Corporation Customer relationships	Jul. 03, 2012 Ember Corporation Customer relationships	Jul. 31, 2012 Ember Corporation Trademarks	Jul. 03, 2012 Ember Corporation Trademarks	Jul. 31, 2012 Ember Corporation In Process research and development	Sep. 29, 2012 Ember Corporation In Process research and development	Jul. 03, 2012 Ember Corporation In Process research and development	Sep. 30, 2012 Headquarters leases item	Sep. 28, 2012 Headquarters leases	Sep. 28, 2012 400 WCC	Sep. 28, 2012 200 WCC
Business acquisition
Purchase price of acquisition			$ 79,000,000
Estimated fair value of contingent consideration			4,000,000
Minimum revenue of acquired products		27,000,000
Number of years over which minimum revenue generate		1 year
Purchase price allocation
Indefinite intangible assets												14,810,000
Finite intangible assets					17,800,000		5,620,000		910,000
Intangible assets			39,140,000
Cash and cash equivalents			3,115,000
Accounts receivable			1,928,000
Inventories			4,749,000
Other current assets			324,000
Goodwill			14,580,000
Non-current deferred tax assets, net			16,530,000
Other non-current assets			1,776,000
Current liabilities			(3,171,000)
Total purchase price			78,971,000
Weighted-Average Amortization Period				11 years		9 years		12 years
Discount rate applicable to the cash flows (as a percent)											12.50%
Estimated costs										11,200,000
Purchase option price for buildings															44,300,000	50,100,000
Buildings														90,900,000
Leasehold interest in ground leases														23,840,000
Acquired unfavorable leases														(11,925,000)
Lease-related charges														(8,000)
Net gain on purchase	(8,457,000)												(8,457,000)
Total purchase price														$ 94,350,000
Useful life of building													40 years
Useful life of leasehold interest in ground leases													86 years
Number of leases purchase price fixed													2