Inventories (Tables)

6 Months Ended

Jun. 30, 2018

Inventories [Abstract]

Inventories

Inventories consisted of the following:

	June 30,		December 31,
(in thousands)	2018		2017
Raw materials and supplies	$	34,426	$	36,069
Work-in-process		79,546		76,610
Finished goods		25,401		30,133
Total inventories	$	139,373	$	142,812