Geographic Information - Net Sales by Geographic Region based on Location of Sales Organization (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net sales by geographic region
Revenues	$ 8,399	$ 8,406	$ 16,613	$ 18,152
United States
Net sales by geographic region
Revenues	5,387	6,513	10,060	12,390
Canada
Net sales by geographic region
Revenues	2,215	1,243	4,904	4,421
Europe
Net sales by geographic region
Revenues	797	650	1,649	1,341
Total international
Net sales by geographic region
Revenues	$ 3,012	$ 1,893	$ 6,553	$ 5,762