Property, Plant and Equipment (Schedule of Property, Plant and Equipment) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 29, 2014	Dec. 28, 2013
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 775,681	$ 770,696
Accumulated depreciation	(475,766)	(465,789)
Property, plant and equipment, net	299,915	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	96,462	97,674
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	636,912	635,638
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	11,340	11,049
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 16,460	$ 11,828