Inventories (Tables)

3 Months Ended

Mar. 31, 2018

Inventory Disclosure [Abstract]

Schedule of Major Components of Inventories

The major components of inventories were as follows:

	March 31, 2018		December 31, 2017
Petroleum products	$	20,048	$	8,731
Crude oil	25,133		29,873
Caustic soda	5,016		5,755
NaHS	9,655		8,277
Raw materials - Alkali operations	4,648		4,550
Work-in-process - Alkali operations	9,747		7,355
Finished goods, net - Alkali operations	10,914		14,075
Materials and supplies, net - Alkali operations	10,498		10,030
Other	8		7
Total	$	95,667	$	88,653