Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Less accumulated depreciation	$ (179)	$ (116)
Property and equipment, net	140	203
Depreciation	63	63	$ 50
Office equipment, leasehold improvements and furniture
Property, Plant and Equipment [Line Items]
Office equipment, leasehold improvements and furniture	$ 319	$ 319