Acquisition (Details) (USD $) Share data in Millions, unless otherwise specified	9 Months Ended			0 Months Ended		0 Months Ended			9 Months Ended		1 Months Ended
	Sep. 29, 2012	Sep. 28, 2013	Dec. 29, 2012	Jul. 01, 2013 Energy Micro	Sep. 28, 2013 Energy Micro	Jul. 01, 2013 Energy Micro Core and developed technology	Jul. 01, 2013 Energy Micro Customer relationships	Jul. 01, 2013 Energy Micro Trademarks	Sep. 28, 2013 Energy Micro In-process research and development	Jul. 01, 2013 Energy Micro In-process research and development	Sep. 30, 2012 Corporate Headquarters Buildings item	Sep. 30, 2012 400 WCC	Sep. 30, 2012 200 WCC
Acquisition
Purchase price of acquisition				$ 140,600,000
Initial consideration				107,400,000
Deferred consideration in the form of a promissory note, fair value				19,200,000
Restricted stock exchanged of promissory note in form of deferred consideration on acquisition				0.5
Mandatory period of creditor notice after which the deferred consideration in the form of a promissory note will be exchanged for the entity's restricted stock				2 months
Earn-Out, fair value				14,000,000
Additional consideration on acquisition				33,300,000
Minimum annual revenue growth for additional consideration (as a percent)				25.00%
Earn out period				5 years
Maximum annual Earn-Out payment				6,666,666
Minimum revenue in single fiscal year from Earn-Out products required to make the entire Earn-Out amount payable				400,000,000
Amount of initial consideration held in escrow by the company as security for breaches of representations and warranties and certain other expressly enumerated matters				20,300,000
Percentage of Earn-Out contingent on the continued employment of certain key employees				28.76%
Period of continued employment of key employees for calculating Earn-out portion following acquisition date				3 years
Acquisition-related costs recorded in selling, general and administrative expenses					2,400,000
Purchase price allocation
Intangible assets				55,400,000		29,100,000	6,400,000	1,300,000		18,600,000
Cash and cash equivalents				919,000
Other current assets				5,516,000
Goodwill		227,289,000	130,265,000	97,023,000
Other non-current assets				5,917,000
Current liabilities				(6,255,000)
Non-current deferred tax liabilities, net				(6,212,000)
Long-term debt				(8,434,000)
Other non-current liabilities				(3,292,000)
Total purchase price				140,582,000							94,350,000
Weighted-Average Amortization Period						7 years	8 years	8 years
Discount rate applicable to the cash flows (as a percent)									13.00%
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)
Useful life of building											40 years
Useful life of leasehold interest in ground leases											86 years
Number of leases for which purchase prices were fixed											2