Shareholders' Equity (Employee Stock-Based Compensation Expense Included In The Consolidated Statements Of Income) (Details) (USD $) In Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Oct. 01, 2010		Sep. 30, 2011		Oct. 01, 2010
Shareholder's Equity [Line Items]
Total stock-based compensation expense	$ 7,105		$ 5,540		$ 21,033		$ 16,165
Tax benefit	(1,782)	[1]	(1,150)	[1]	(6,124)	[1]	(3,345)	[1]
Total stock-based compensation expense, net of tax	5,323		4,390		14,909		12,820
Cost Of Sales [Member]
Shareholder's Equity [Line Items]
Total stock-based compensation expense	491		485		1,461		1,472
Research And Development [Member]
Shareholder's Equity [Line Items]
Total stock-based compensation expense	1,151		968		3,373		2,899
Sales And Marketing [Member]
Shareholder's Equity [Line Items]
Total stock-based compensation expense	1,672		1,283		4,966		4,013
General And Administrative [Member]
Shareholder's Equity [Line Items]
Total stock-based compensation expense	3,791		2,804		11,233		7,781
Total Operating Expenses [Member]
Shareholder's Equity [Line Items]
Total stock-based compensation expense	$ 6,614		$ 5,055		$ 19,572		$ 14,693

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