Geographic Information - Net Sales by Geographic Region based on Location of Sales Organization (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net sales by geographic region
Revenues	$ 6,857	$ 10,132	$ 23,470	$ 28,284
United States
Net sales by geographic region
Revenues	3,909	7,354	13,969	18,719
Canada
Net sales by geographic region
Revenues	1,844	2,084	6,748	7,143
Europe
Net sales by geographic region
Revenues	1,104	694	2,753	2,422
Total international
Net sales by geographic region
Revenues	$ 2,948	$ 2,778	$ 9,501	$ 9,565