Inventories (Tables)

3 Months Ended

Mar. 31, 2018

Inventories Disclosure [Abstract]

Schedule of Inventory [Table Text Block]

			March 31,		December 31,
			2018		2017
			(in thousands)
Finished goods		$	7,652	$	5,779
Work in process			4,786		1,042
Raw materials			15,464		10,027
	Total	$	27,902	$	16,848