Earnings Per Share (Schedule Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Earnings Per Share [Abstract]
Net (loss) earnings available to common stockholders	$ (3,991)	$ (4,075)	$ (16,042)	$ 5,650
Weighted-average number of common shares outstanding (shares)	42,106	41,714	42,010	41,644
Shares issuable under deferred compensation agreements (shares)	869	376	854	361
Basic weighted-average number of common shares outstanding (shares)	42,975	42,090	42,864	42,005
Common shares assumed upon exercise of stock options and awards (shares)	0	0	0	304
Unvested shares issuable under deferred compensation arrangements (shares)	0	0	0	12
Dilutive weighted-average number of common shares outstanding (shares)	42,975	42,090	42,864	42,321
Basic (loss) earnings per share (USD per share)	$ (0.09)	$ (0.10)	$ (0.37)	$ 0.13
Diluted (loss) earnings per share (USD per share)	$ (0.09)	$ (0.10)	$ (0.37)	$ 0.13