Employee Benefit Plans (Schedule Of Total Stock-Based Compensation Expense Resulting From Stock Options, Restricted Stock Awards, And The Employee Stock Purchase Plan) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 4,058	$ 4,934	$ 8,406	$ 10,064
Cost Of Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	336	489	832	960
Research And Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	773	1,227	1,618	2,623
Sales And Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,272	1,401	2,665	3,350
General And Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,677	$ 1,817	$ 3,291	$ 3,131