Net Income Per Share (Schedule Of Net Income Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Apr. 01, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income	$ 15,343	$ 25,147
Weighted average shares outstanding: Basic (in shares)	38,433,000	37,796,000
Weighted average shares outstanding: Dilutive potential common shares (in shares)	617,000	780,000
Weighted average shares outstanding: Total diluted shares (in shares)	39,050,000	38,576,000
Basic net income per share (in dollars per share)	$ 0.40	$ 0.67
Diluted net income per share (in dollars per share)	$ 0.39	$ 0.65
Anti-dilutive common stock options (in shares)	2,400,000	1,800,000