Investments (Details) (USD $) In Thousands, unless otherwise specified	Sep. 27, 2014	Dec. 28, 2013
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	$ 1,338,707	$ 1,287,802
Gross Unrealized Gains	188	715
Gross Unrealized Losses	(490)	(367)
Fair Value	1,338,405	1,288,150
Cash equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	289,432	68,435
Gross Unrealized Gains
Gross Unrealized Losses
Fair Value	289,432	68,435
Cash equivalents [Member] | Money market funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	213,003	57,254
Gross Unrealized Gains
Gross Unrealized Losses
Fair Value	213,003	57,254
Cash equivalents [Member] | Time deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	11,354	7,771
Gross Unrealized Gains
Gross Unrealized Losses
Fair Value	11,354	7,771
Cash equivalents [Member] | Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	62,575	3,000
Gross Unrealized Gains
Gross Unrealized Losses
Fair Value	62,575	3,000
Cash equivalents [Member] | Government and corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	2,500	410
Gross Unrealized Gains
Gross Unrealized Losses
Fair Value	2,500	410
Short-term investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	835,283	676,723
Gross Unrealized Gains	140	369
Gross Unrealized Losses	(154)	(88)
Fair Value	835,269	677,004
Short-term investments [Member] | Time deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	83,402	70,303
Gross Unrealized Gains	1	12
Gross Unrealized Losses	(8)
Fair Value	83,395	70,315
Short-term investments [Member] | Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	441,455	33,750
Gross Unrealized Gains	8	1
Gross Unrealized Losses	(98)	(9)
Fair Value	441,365	33,742
Short-term investments [Member] | Government and corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	310,426	572,670
Gross Unrealized Gains	131	356
Gross Unrealized Losses	(48)	(79)
Fair Value	310,509	572,947
Long-term investments [Member] | Government and corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost	213,992	542,644
Gross Unrealized Gains	48	346
Gross Unrealized Losses	(336)	(279)
Fair Value	$ 213,704	$ 542,711