Property, Plant and Equipment (Schedule of Property, Plant and Equipment) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 28, 2014	Dec. 28, 2013
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 775,325	$ 770,696
Accumulated depreciation	(482,519)	(465,789)
Property, plant and equipment, net	292,806	304,907
Land and land improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	14,507	14,507
Building and building improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	95,346	97,674
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	633,785	635,638
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	11,531	11,049
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 20,156	$ 11,828