Net Income Per Share (Schedule Of Net Income Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014
Earnings Per Share [Abstract]
Net income	$ 3,667	$ 14,705	$ 11,678	$ 29,116
Weighted average shares outstanding: Basic (in shares)	33,792	36,139	34,227	36,381
Potentially dilutive common share equivalent (in shares)	516	669	563	671
Weighted average common shares outstanding: dilutive (in shares)	34,308	36,808	34,790	37,052
Basic net income per share (in dollars per share)	$ 0.11	$ 0.41	$ 0.34	$ 0.80
Diluted net income per share (in dollars per share)	$ 0.11	$ 0.40	$ 0.34	$ 0.79
Anti-dilutive employee stock-based awards, excluded (in shares)	2,631	2,521	2,440	2,529