Inventories (Tables)

9 Months Ended

Sep. 30, 2018

Inventory Disclosure [Abstract]

Schedule of Inventories

Inventories were comprised of the following:

	September 30, 2018		December 31, 2017
Raw materials	$	22,113	$	24,249
Work-in-process		44,459		42,840
Finished goods		22,705		24,083
Supplies		17,925		16,389
Inventories	$	107,202	$	107,561