Earnings Per Share (Schedule Of Earnings 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 (loss) earnings available to common stockholders	$ (5,407)	$ 9,854	$ (6,152)	$ 9,725
Weighted-average number of common shares outstanding (shares)	42,071	41,678	41,961	41,609
Shares issuable under deferred compensation agreements (shares)	885	360	845	353
Basic weighted-average number of common shares outstanding (shares)	42,956	42,038	42,806	41,962
Common shares assumed upon exercise of stock options and awards (shares)	0	273	0	308
Unvested shares issuable under deferred compensation arrangements (shares)	0	13	0	17
Dilutive weighted-average number of common shares outstanding (shares)	42,956	42,324	42,806	42,287
Basic loss per share (USD per share)	$ (0.13)	$ 0.23	$ (0.14)	$ 0.23
Diluted loss per share (USD per share)	$ (0.13)	$ 0.23	$ (0.14)	$ 0.23