Inventories (Tables)

9 Months Ended

Sep. 30, 2018

Inventory Disclosure [Abstract]

Schedule of Inventory, Current [Table Text Block]

Components of inventories as of September 30, 2018 and December 31, 2017 are as follows: 

	September 30, 2018		December 31, 2017
	(In Thousands)
Finished goods	$	67,926	$	66,377
Raw materials	3,740		4,027
Parts and supplies	45,671		33,632
Work in progress	33,301		11,402
Total inventories	$	150,638	$	115,438