Property and Equipment, Net (Schedule of Property and Equipment, Net) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Property and Equipment [Line Items]
Property and equipment	$ 1,347,600	$ 1,182,200
Less accumulated depreciation and amortization	(699,100)	(633,100)
Property and equipment, net	648,456	549,084
Land [Member]
Property and Equipment [Line Items]
Property and equipment	4,600	4,600
Building and Leasehold Improvements [Member]
Property and Equipment [Line Items]
Property and equipment	26,200	24,200
Machinery and Equipment [Member]
Property and Equipment [Line Items]
Property and equipment	1,155,600	997,800
Office Furniture and Equipment [Member]
Property and Equipment [Line Items]
Property and equipment	148,900	146,100
Construction in Progress [Member]
Property and Equipment [Line Items]
Property and equipment	$ 12,300	$ 9,500