Restructuring and Exit Costs (Details Textual) ft² in Thousands, $ in Thousands	3 Months Ended			7 Months Ended	12 Months Ended
	Mar. 31, 2018 USD ($)	Sep. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jun. 30, 2015 ft²
Restructuring Cost and Reserve [Line Items]
Restructuring and exit costs	$ (57)		$ 997
Lease Obligation Costs
Restructuring Cost and Reserve [Line Items]
Restructuring and exit costs		$ 200
Amount of liability	600			$ 600	$ 700
September 2017 Restructuring Plan | Restructuring and exit costs
Restructuring Cost and Reserve [Line Items]
Restructuring and exit costs	(57)			1,200
September 2017 Restructuring Plan | Employee Severance Costs
Restructuring Cost and Reserve [Line Items]
Restructuring and exit costs	45				1,275
Restructuring Reserve, Accrual Adjustment	102				27
Cash payments with restructuring plan	423				431
Amount of liability	337			337	817	$ 0
February 2017 Restructuring Plan | Restructuring and exit costs
Restructuring Cost and Reserve [Line Items]
Restructuring and exit costs			1,000		900
February 2017 Restructuring Plan | Employee Severance Costs
Restructuring Cost and Reserve [Line Items]
Restructuring and exit costs	0				997
Restructuring Reserve, Accrual Adjustment	0				142
Cash payments with restructuring plan	0		$ 300		855
Amount of liability	$ 0			$ 0	$ 0	$ 0
2015 Consolidation of US Manufacturing Operations | Lease Obligation Costs
Restructuring Cost and Reserve [Line Items]
Square feet of manufacturing facility | ft²							60