Property, Plant and Equipment - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 900	$ 600	$ 2,700	$ 1,703
Interest costs capitalized			0	2,013
Construction in progress
Property, Plant and Equipment [Line Items]
Interest costs capitalized		1,500		4,400
Payroll costs	$ 300	$ 400	$ 900	$ 1,500