Inventories (Tables)

9 Months Ended

Sep. 30, 2017

Inventory, Net [Abstract]

Schedule of Inventories

Inventories consist of the following:
	September 30, 2017		December 31, 2016
Raw materials	$	70,915	$	59,415
Work-in-process	42,920		35,539
Finished goods	34,055		26,613
Operating and other supplies	113,866		111,996
Total inventories	$	261,756	$	233,563