Property and Equipment (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation	$ 153	$ 37	$ 325	$ 104
Accumulated depreciation	931		931		$ 355
Inventories
Property, Plant and Equipment [Line Items]
Accumulated depreciation	238		238
Prepaid Expenses and Other Current Assets
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ 23		$ 23