Inventory (Tables)

6 Months Ended

Jun. 30, 2018

Inventory Disclosure [Abstract]

Schedule of Inventory

The major classes of inventory were as follows:

	June 30, 2018		December 31, 2017
	(in thousands)
Raw materials	$	919	$	1,389
Work-in-progress	2,501		3,608
Finished goods	269		562
Total	$	3,689	$	5,559