Property, Plant and Equipment (Schedule of Property, Plant and Equipment) (Details) - USD ($) $ in Thousands	Jun. 27, 2015	Dec. 27, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 762,468	$ 762,248
Accumulated depreciation	(491,526)	(479,840)
Property, plant and equipment, net	270,942	282,408
Land and land improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	13,982	13,982
Building and building improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	103,029	101,407
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	618,312	623,619
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	9,580	10,086
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 17,565	$ 13,154