Inventories

12 Months Ended

Dec. 31, 2017

Inventory, Net [Abstract]

Inventories

Inventories

Inventories, at December 31, consist of the following:

	2017		2016
Raw materials	$	106,210	$	59,415
Work-in-process	49,584		35,539
Finished goods	40,852		26,613
Operating and other supplies	120,823		111,996
Inventories	$	317,469	$	233,563