Stock-Based Compensation Expense (Details 2) (USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended
	Jul. 01, 2012
Changes in stock options outstanding
Options outstanding at December 31, 2011, Number of Shares	64,245
Assumed in Sand Force acquisition, Number of shares	7,542
Options granted, Number of shares	5,033
Options exercised, Number of shares	(11,942)
Options cancelled, Number of shares	(2,757)
Options outstanding at July 1,2012, Number of Shares	62,121
Options exercisable at July 1,2012, Number of shares	37,288
Options outstanding at December 31, 2011, Weighted-Average Exercise Price Per Share	$ 6.19
Assumed in Sand Force acquisition, Weighted Average Exercise Price Per Share	$ 0.75
Options granted, Weighted-Average Exercise Price Per Share	$ 8.50
Options exercised, Weighted-Average Exercise Price Per Share	$ 5.69
Options cancelled, Weighted-Average Exercise Price Per Share	$ 9.32
Options outstanding at July 1,2012, Weighted-Average Exercise Price Per Share	$ 5.67
Options exercisable at July 1, 2012, Weighted-Average Exercise Price Per Share	$ 6.15
Options outstanding at July 1,2012, Weighted-Average Remaining Contractual Term	4 years 1 month 2 days
Options exercisable at July 1,2012, Weighted-Average Remaining Contractual Term	2 years 9 months 22 days
Options outstanding at July 1,2012, Aggregate Intrinsic Value	$ 91,608
Options exercisable at July 1,2012, Aggregate Intrinsic Value	$ 43,806