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
	Apr. 02, 2017	Apr. 03, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 5,128	$ 4,411
Cost Of Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	436	439
Research And Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,319	866
Sales And Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,247	1,197
General And Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,126	$ 1,909