Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 7,222	$ 14,461
Less accumulated depreciation	(6,508)	(13,303)
Property and equipment, net	714	1,158
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,735	2,124
Computer hardware and software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,213	1,228
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	4,274	11,078
Vehicles
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 0	$ 31