Intangible Assets - Schedule of Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Gross Carrying Amount	$ 5,062	$ 5,053
Accumulated Amortization	(3,839)	(3,768)
Finite-Lived Intangible Assets, Net	1,223	1,285
Patent [Member]
Gross Carrying Amount	735	728
Accumulated Amortization	(344)	(336)
Finite-Lived Intangible Assets, Net	$ 391	392
Patent [Member] \| Minimum [Member]
Finite-Lived Intangible Asset, Useful Life	1 year
Patent [Member] \| Maximum [Member]
Finite-Lived Intangible Asset, Useful Life	17 years
Software [Member]
Finite-Lived Intangible Asset, Useful Life	3 years
Gross Carrying Amount	$ 412	410
Accumulated Amortization	(404)	(403)
Finite-Lived Intangible Assets, Net	$ 8	7
Customer Relationships [Member]
Finite-Lived Intangible Asset, Useful Life	10 years
Gross Carrying Amount	$ 3,370	3,370
Accumulated Amortization	(2,546)	(2,491)
Finite-Lived Intangible Assets, Net	$ 824	879
Permit [Member]
Finite-Lived Intangible Asset, Useful Life	10 years
Gross Carrying Amount	$ 545	545
Accumulated Amortization	(545)	(538)
Finite-Lived Intangible Assets, Net		$ 7