Property, Plant and Equipment (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant And Equipment [Abstract]
Impairment of long lived assets	$ 49,198
Leasehold Improvements, Gross	74,900	$ 73,600
Depreciation	$ 374,500	$ 419,200	$ 486,900