Property and Equipment, net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 1,027		$ 1,027		$ 731
Less: Accumulated depreciation	(388)		(388)		(235)
Property and equipment, Net	639		639		496
Depreciation of property and equipment	53	$ 39	153	$ 154
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	329		329		329
Office and other equipment
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	222		222		56
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	425		425		346
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 51		$ 51		$ 0