Summary of Significant Accounting Policies - PP&E, ARO and Other (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment
Construction in progress	$ 45,555	$ 14,930
Interest costs capitalized	0	0
Capitalized cost in accounts payable and accrued expenses	936	2,787
Asset Retirement Obligations
ARO included in other liabilities and accrued expenses	1,519	1,582
Amount of assets associated with AROs not fully depreciated	877
Amount spent on AROs	178	377
Accretion expense recognized on AROs	84	73	$ 70
Other Assets
Deferred financing costs	19	35
Other	530	678
Total	549	713
Environmental Expenditures
Capital expenditures related to environmental matters	1,152	$ 440	$ 477
Minimum
Asset Retirement Obligations
Estimated annual expenditures in years 2018 through 2022 relating to AROs	100
Maximum
Asset Retirement Obligations
Estimated annual expenditures in years 2018 through 2022 relating to AROs	$ 200
Buildings and building and leasehold improvements. | Minimum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	3 years
Buildings and building and leasehold improvements. | Maximum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	25 years
Machinery and equipment | Minimum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	2 years
Machinery and equipment | Maximum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	25 years
Furniture and fixtures | Minimum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	3 years
Furniture and fixtures | Maximum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	10 years
Automotive equipment. | Minimum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	3 years
Automotive equipment. | Maximum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	10 years