Inventories

9 Months Ended

Sep. 30, 2017

Inventory, Net [Abstract]

Inventories

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

Inventories are stated at the lower of cost or Net Realizable Value ("NRV") using the first-in, first-out ("FIFO") or the weighted average cost method.