Intangible Assets - Summary of Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 14,261	$ 14,985
Accumulated Amortization	(7,949)	(7,781)
Net Carrying Amount	6,312	7,204
Total	16,241	17,389
Net	8,292	9,608
Licenses
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,414	1,414
Accumulated Amortization	(1,099)	(1,066)
Net Carrying Amount	315	348
Patents and know-how
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	8,966	9,180
Accumulated Amortization	(4,589)	(4,475)
Net Carrying Amount	4,377	4,705
Customer and supplier relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,761	4,271
Accumulated Amortization	(2,216)	(2,202)
Net Carrying Amount	1,545	2,069
Non compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	120	120
Accumulated Amortization	(45)	(38)
Net Carrying Amount	75	82
Trade names and trademarks
Finite-Lived Intangible Assets [Line Items]
Gross carrying value, indefinite lived	1,008	1,008
Patents in process
Finite-Lived Intangible Assets [Line Items]
Gross carrying value, indefinite lived	$ 972	$ 1,396