Investments and Fair Value Measurements-Fin Assets and Liabilities 2 (Details 3) - USD ($)		Sep. 27, 2015	Dec. 28, 2014
Financial assets measured at fair value on a recurring basis
Short-term marketable securities		$ 1,000,621,000	$ 1,455,509,000
Long-term marketable securities		2,176,095,000	2,758,475,000
Other current assets		210,815,000	214,992,000
Significant Unobservable Inputs (Level 3) [Member]
Financial assets measured at fair value on a recurring basis
Total financial assets		0	0
Financial Liabilities measured at fair value on a recurring basis
Total financial liabilities		0	0
Fair Value, Measurements, Recurring [Member]
Financial assets measured at fair value on a recurring basis
Total financial assets		3,666,787,000	4,776,694,000
Financial Liabilities measured at fair value on a recurring basis
Total financial liabilities		1,723,000	8,224,000
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets measured at fair value on a recurring basis
Total financial assets		466,206,000	558,295,000
Financial Liabilities measured at fair value on a recurring basis
Total financial liabilities		0	0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Financial assets measured at fair value on a recurring basis
Total financial assets		3,200,581,000	4,218,399,000
Financial Liabilities measured at fair value on a recurring basis
Total financial liabilities		1,723,000	8,224,000
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial assets measured at fair value on a recurring basis
Total financial assets		0	0
Financial Liabilities measured at fair value on a recurring basis
Total financial liabilities		0	0
Other current accrued liabilities [Member] | Fair Value, Measurements, Recurring [Member]
Financial Liabilities measured at fair value on a recurring basis
Other current accrued liabilities		1,723,000	8,224,000
Other current accrued liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial Liabilities measured at fair value on a recurring basis
Other current accrued liabilities		0	0
Other current accrued liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Financial Liabilities measured at fair value on a recurring basis
Other current accrued liabilities		1,723,000	8,224,000
Other current accrued liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial Liabilities measured at fair value on a recurring basis
Other current accrued liabilities		0	0
Cash equivalents [Member] | Fair Value, Measurements, Recurring [Member]
Financial assets measured at fair value on a recurring basis
Cash equivalents(1)	[1]	484,432,000	557,910,000
Cash equivalents [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets measured at fair value on a recurring basis
Cash equivalents(1)	[1]	458,566,000	533,133,000
Cash equivalents [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Financial assets measured at fair value on a recurring basis
Cash equivalents(1)	[1]	25,866,000	24,777,000
Cash equivalents [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial assets measured at fair value on a recurring basis
Cash equivalents(1)	[1]	0	0
Short-term marketable securities [Member] | Fair Value, Measurements, Recurring [Member]
Financial assets measured at fair value on a recurring basis
Short-term marketable securities		1,000,621,000	1,455,509,000
Short-term marketable securities [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets measured at fair value on a recurring basis
Short-term marketable securities		820,000	3,327,000
Short-term marketable securities [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Financial assets measured at fair value on a recurring basis
Short-term marketable securities		999,801,000	1,452,182,000
Short-term marketable securities [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial assets measured at fair value on a recurring basis
Short-term marketable securities		0	0
Long term marketable securities [Member] | Fair Value, Measurements, Recurring [Member]
Financial assets measured at fair value on a recurring basis
Long-term marketable securities		2,176,095,000	2,758,475,000
Long term marketable securities [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets measured at fair value on a recurring basis
Long-term marketable securities		6,820,000	21,835,000
Long term marketable securities [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Financial assets measured at fair value on a recurring basis
Long-term marketable securities		2,169,275,000	2,736,640,000
Long term marketable securities [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial assets measured at fair value on a recurring basis
Long-term marketable securities		0	0
Other current assets [Member] | Fair Value, Measurements, Recurring [Member]
Financial assets measured at fair value on a recurring basis
Other current assets		5,639,000	4,800,000
Other current assets [Member] | Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets measured at fair value on a recurring basis
Other current assets		0	0
Other current assets [Member] | Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Financial assets measured at fair value on a recurring basis
Other current assets		5,639,000	4,800,000
Other current assets [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial assets measured at fair value on a recurring basis
Other current assets		$ 0	$ 0

[1] Cash equivalents exclude cash holdings of $213.6 million and $251.1 million included in Cash and cash equivalents on the Condensed Consolidated Balance Sheets as of September 27, 2015 and December 28, 2014, respectively.