PROPERTY, PLANT AND EQUIPMENT (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 25, 2010
Property, Plant and Equipment
Property, plant and equipment, at cost	$ 911,642	$ 865,287
Land and improvements
Property, Plant and Equipment
Property, plant and equipment, at cost	64,001	59,965
Buildings and improvements
Property, Plant and Equipment
Property, plant and equipment, at cost	229,389	219,890
Machinery and equipment
Property, Plant and Equipment
Property, plant and equipment, at cost	475,292	467,466
Transportation equipment
Property, Plant and Equipment
Property, plant and equipment, at cost	33,927	30,156
Office furniture and equipment
Property, Plant and Equipment
Property, plant and equipment, at cost	75,229	70,867
Construction in progress
Property, Plant and Equipment
Property, plant and equipment, at cost	$ 33,804	$ 16,943