Property, Plant and Equipment (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Capitalized interest included in property, plant and equipment	$ 5,608	$ 7,091	$ 9,202
Depreciation expense	366,233	328,486	$ 315,840
Capital leases included in the property, plant and equipment, cost	7,986	8,233
Capital leases included in the property, plant and equipment, accumulated depreciation	$ 4,436	$ 4,431