Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 6,003	$ 6,679
Less accumulated depreciation	(4,781)	(4,552)
Property and equipment, net	1,222	2,127
Laboratory equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	4,836	5,379
Computer equipment and software
Property, Plant and Equipment [Line Items]
Total property and equipment	515	561
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	278	278
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	237	247
Office equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	135	135
Construction in process
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 2	$ 79