Shareholders' Equity (Summary Of Stock-Based Compensation Expense, Net Of Tax) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2012		Apr. 01, 2011
Shareholders' Equity [Line Items]
Total stock-based compensation expense	$ 7,789		$ 6,798
Tax benefit	(2,473)	[1]	(2,203)	[1]
Total stock-based compensation expense, net of tax	5,316		4,595
Cost Of Sales [Member]
Shareholders' Equity [Line Items]
Total stock-based compensation expense	520		468
Research And Development [Member]
Shareholders' Equity [Line Items]
Total stock-based compensation expense	1,229		1,096
Sales And Marketing [Member]
Shareholders' Equity [Line Items]
Total stock-based compensation expense	1,791		1,634
General And Administrative [Member]
Shareholders' Equity [Line Items]
Total stock-based compensation expense	4,249		3,600
Total Operating Expenses [Member]
Shareholders' Equity [Line Items]
Total stock-based compensation expense	$ 7,269		$ 6,330

[1] Tax benefit related to U.S. incentive and non-qualified stock options, restricted stock units and ESPP, applying a Federal statutory and State (Federal effected) tax rate for the respective periods.