Other Current Assets Schedule of Other Current Assets (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2018 USD ($) parcelofland	Dec. 31, 2017 USD ($) parcelofland
Property, Plant and Equipment [Line Items]
Prepaid expenses	$ 20,306	$ 20,306	$ 14,205
Other current assets	3,857	3,857	4,762
Land held for sale	7,000	7,000	7,000
Total	31,163	31,163	$ 25,967
Parcels of land, sold | parcelofland			1
Property, plant and equipment, book value	117,610	$ 117,610	$ 83,374
Parcels of land, held for sale | parcelofland		1
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, book value	3,000	$ 3,000
Gain on sale of equipment	$ 82