Summary Of Significant Accounting Policies (Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014	Dec. 28, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
(Loss) earnings before income taxes	$ (6,105)	$ 11,631	$ (6,779)	$ 12,722
Tax benefit	698	(1,777)	627	(2,997)
Net (loss) earnings	(5,407)	9,854	(6,152)	9,725	$ 10,953
Reclassification Out Of Accumulated Other Comprehensive Income (Loss) | Amortization of pension plan items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Actuarial loss	(733)	(386)	(1,483)	(771)
Prior service cost	(7)	(3)	(13)	(6)
(Loss) earnings before income taxes	(740)	(389)	(1,496)	(777)
Tax benefit	432	112	435	222
Net (loss) earnings	$ (308)	$ (277)	$ (1,061)	$ (555)