Balance Sheet Account Details (Details) (USD $) In Thousands, unless otherwise specified	Sep. 28, 2014	Dec. 29, 2013
Available-for-sale securities:
Available for sale securities, Amortized Cost	$ 443,028	$ 454,055
Available for sale securities, Gross Unrealized Gains	200	388
Available for sale securities, Gross Unrealized Losses	(1,696)	(477)
Available for sale securities, Estimated Fair Value	441,532	453,966
Debt securities in government sponsored entities [Member]
Available-for-sale securities:
Available for sale securities, Amortized Cost	46,021	82,226
Available for sale securities, Gross Unrealized Gains	17	18
Available for sale securities, Gross Unrealized Losses	(47)	(101)
Available for sale securities, Estimated Fair Value	45,991	82,143
Corporate debt securities [Member]
Available-for-sale securities:
Available for sale securities, Amortized Cost	332,735	342,034
Available for sale securities, Gross Unrealized Gains	136	312
Available for sale securities, Gross Unrealized Losses	(1,621)	(376)
Available for sale securities, Estimated Fair Value	331,250	341,970
U.S. Treasury securities [Member]
Available-for-sale securities:
Available for sale securities, Amortized Cost	64,272	29,795
Available for sale securities, Gross Unrealized Gains	47	58
Available for sale securities, Gross Unrealized Losses	(28)
Available for sale securities, Estimated Fair Value	$ 64,291	$ 29,853