Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accrued Liabilities.
Property, plant and equipment	$ 7,612	$ 182
Employee related expenses	4,829	1,237
Selling, general and administrative	1,507	78
Cost of sales	825	107
Excise, franchise and sales taxes	608	83
Ad valorem taxes	15	440
Other	72	17
Accrued liabilities	$ 15,468	$ 2,144