PROPERTY AND EQUIPMENT, NET - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 13,223	$ 15,367
Less: Accumulated depreciation and amortization	(10,786)	(11,870)
Property and equipment, net	2,437	3,497
Furniture and office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,680	2,557
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	0	2,731
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	20	221
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 10,523	$ 9,858