Intangible Assets and Goodwill - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite Lived And Indefinite Lived Intangible Assets By Major Class [Line Items]
Less accumulated amortization	$ (4,733)	$ (3,557)
Total net amortizable intangibles	2,750	3,538
Intangible assets, net of accumulated amortization	3,266	4,054
Amortization expense	1,052	1,067	$ 735
Trademarks and other
Finite Lived And Indefinite Lived Intangible Assets By Major Class [Line Items]
Non-amortizable intangibles	$ 516	516
Distribution agreement
Finite Lived And Indefinite Lived Intangible Assets By Major Class [Line Items]
Amorizable Intangibles, useful lives	2 years
Amorizable Intangibles, gross	$ 3,021	3,021
Certification
Finite Lived And Indefinite Lived Intangible Assets By Major Class [Line Items]
Amorizable Intangibles, useful lives	7 years
Amorizable Intangibles, gross	$ 350	350
Customer relationships
Finite Lived And Indefinite Lived Intangible Assets By Major Class [Line Items]
Amorizable Intangibles, useful lives	12 years
Amorizable Intangibles, gross	$ 1,191	1,086
Patents and processes
Finite Lived And Indefinite Lived Intangible Assets By Major Class [Line Items]
Amorizable Intangibles, useful lives	10 years
Amorizable Intangibles, gross	$ 1,998	1,797
Brand names
Finite Lived And Indefinite Lived Intangible Assets By Major Class [Line Items]
Amorizable Intangibles, useful lives	15 years
Amorizable Intangibles, gross	$ 923	$ 841