Inventories (Tables)

3 Months Ended

Mar. 31, 2018

Inventory Disclosure [Abstract]

Schedule of inventories

Inventories at March 31, 2018 and December 31, 2017 consisted of the following:

(in thousands)	March 31, 2018		December 31, 2017
Raw material	$	1,967	$	2,148
Work-in-process	3,456		6,585
Finished goods	14,476		14,647
Supplies	713		729
Total inventories	$	20,612	$	24,109