Summary Of Significant Accounting Policies (Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 27, 2015	Sep. 27, 2015	Jun. 28, 2015	Mar. 29, 2015	Dec. 28, 2014	Sep. 28, 2014	Jun. 29, 2014	Mar. 30, 2014	Dec. 27, 2015	Dec. 28, 2014	Dec. 29, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Prior service cost									$ 240	$ 306
Net (loss) earnings from continuing operations	$ (10,173)	$ (3,991)	$ (9,492)	$ (2,559)	$ 5,303	$ (4,075)	$ 9,854	$ (129)	(26,215)	10,953	$ (1,771)
Tax expense									(7,640)	$ (23,221)	$ (3,671)
Reclassification Out Of Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net of tax									(2,960)
Reclassification Out Of Accumulated Other Comprehensive Income (Loss) | Amortization of pension plan items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Actuarial loss									(2,947)
Prior service cost									(26)
Net (loss) earnings from continuing operations									(2,973)
Tax expense									13
Net of tax									$ (2,960)