Inventory (Tables)

12 Months Ended

Dec. 31, 2017

Inventory Disclosure [Abstract]

Schedule of Inventory

The major classes of inventory were as follows:

	2017		2016
	(In thousands)
Raw materials	$	1,389	$	18,714
Work-in-progress	3,608		8,397
Finished goods	562		1,375
Total	$	5,559	$	28,486