Net Income Per Share (Schedule Of Net Income Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2014	Sep. 29, 2013	Sep. 28, 2014	Sep. 29, 2013
Earnings Per Share [Abstract]
Net income	$ 20,025	$ 14,457	$ 49,141	$ 43,785
Weighted average shares outstanding: Basic (in shares)	35,643,000	38,700,000	36,133,000	38,562,000
Weighted average shares outstanding: Dilutive potential common shares (in shares)	607,000	498,000	673,000	565,000
Weighted average shares outstanding: Total diluted shares (in shares)	36,250,000	39,198,000	36,806,000	39,127,000
Basic net income per share (in dollars per share)	$ 0.56	$ 0.37	$ 1.36	$ 1.14
Diluted net income per share (in dollars per share)	$ 0.55	$ 0.37	$ 1.34	$ 1.12
Anti-dilutive common stock options (in shares)	2,800,000	3,000,000	2,600,000	2,800,000