PROPERTY AND EQUIPMENT - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 23,837	$ 26,945
Less: Accumulated depreciation and amortization	(10,773)	(13,921)
Property and equipment, net	13,064	13,024
Furniture and office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,237	5,986
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	11,391	10,783
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	351	3,335
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 9,858	$ 6,841