Property and Equipment (Summary of Property and Equipment) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,053	$ 1,815
Less: accumulated depreciation	(1,249)	(923)
Total property and equipment, net	804	892
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	399	333
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	271	166
Computers and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	903	836
Field trailers
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10	10
Design center
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 470	$ 470