PROPERTY, PLANT AND EQUIPMENT (Schedule of Property, Plant and Equipment) (Details) - USD ($) $ in Thousands	Dec. 25, 2016	Dec. 27, 2015
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 3,354,504	$ 3,100,144
Accumulated depreciation	(1,848,564)	(1,747,615)
Property, plant and equipment, net	1,505,940	1,352,529
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	112,132	105,165
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,169,984	1,131,379
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,789,550	1,657,573
Autos and trucks [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	50,964	53,408
Construction-in-progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 231,874	$ 152,619