Geographic Information - Net Sales by Geographic Region (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 28,353	$ 36,839
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	17,238	23,870
Total international
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	11,115	12,969
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	7,477	9,583
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 3,638	$ 3,386