Inventories (Tables)

6 Months Ended

Jun. 30, 2017

Inventory Disclosure [Abstract]

Schedule of Inventories

At June 30, 2017 and December 31, 2016, inventories (in thousands) consisted of the following:

	June 30,   2017		December 31,    2016
Supplies	$	19,668	$	18,824
Raw materials and work in process	22,442		25,161
Finished goods	32,168		34,724
Total inventories	$	74,278	$	78,709