Cash, Cash Equivalents and Investments (Details 2) (USD $) In Thousands	Jul. 02, 2011	Jan. 01, 2011
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months	$ 23,650	$ 58,386
Fair value of available-for-sale securities, continuous loss position for twelve month or longer	17,196	18,798
Total fair value of available-for-sale securities, continuous loss position	40,846	77,184
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses	(23)	(69)
Available-for-sale securities, continuous loss position for 12 months or greater, gross unrealized losses	(2,229)	(2,227)
Available-for-sale securities, total gross unrealized losses	(2,252)	(2,296)
Cost
Due in one year or less, Cost	199,095
Due after one year through ten years, Cost	63,813
Due after ten years, Cost	54,950
Total Cost	317,858
Fair Value
Due in one year or less, Fair Value	199,279
Due after one year through ten years, Fair Value	64,196
Due after ten years, Fair Value	52,721
Total Fair Value	316,196
Municipal bonds
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months	6,354	22,272
Total fair value of available-for-sale securities, continuous loss position	6,354	22,272
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses	(3)	(18)
Available-for-sale securities, total gross unrealized losses	(3)	(18)
Auction rate securities
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for twelve month or longer	17,196	17,500
Total fair value of available-for-sale securities, continuous loss position	17,196	17,500
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for 12 months or greater, gross unrealized losses	(2,229)	(2,225)
Available-for-sale securities, total gross unrealized losses	(2,229)	(2,225)
U.S. government agency
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months	6,003	17,007
Total fair value of available-for-sale securities, continuous loss position	6,003	17,007
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses	(2)	(5)
Available-for-sale securities, total gross unrealized losses	(2)	(5)
Corporate bonds
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months	6,279	17,538
Fair value of available-for-sale securities, continuous loss position for twelve month or longer		1,298
Total fair value of available-for-sale securities, continuous loss position	6,279	18,836
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses	(17)	(44)
Available-for-sale securities, continuous loss position for 12 months or greater, gross unrealized losses		(2)
Available-for-sale securities, total gross unrealized losses	(17)	(46)
Certificates of deposit
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months		1,569
Total fair value of available-for-sale securities, continuous loss position		1,569
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses		(2)
Available-for-sale securities, total gross unrealized losses		(2)
International government bonds
Continuous unrealized loss position, Fair Value
Fair value of available-for-sale securities, continuous loss position for less than twelve months	5,014
Total fair value of available-for-sale securities, continuous loss position	5,014
Continuous unrealized loss position, Gross Unrealized Losses
Available-for-sale securities, continuous loss position for less than 12 months, gross unrealized losses	(1)
Available-for-sale securities, total gross unrealized losses	$ (1)