Inventories (Tables)

12 Months Ended

Dec. 31, 2018

Inventories

Schedule of inventories

	December 31,
	2018		2017
	(in thousands)
Materials	$	90,816	$	59,919
Work-in-process		42,354		37,222
Finished goods		23,141		23,125
Total	$	156,311	$	120,266