Certain Balance Sheet Accounts - Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total cost	$ 10,764		$ 10,764
Less accumulated depreciation and amortization	(9,311)		(9,033)
Total property and equipment, net	1,453		1,731
Depreciation and amortization	278	$ 390
Finance leases
Property, Plant and Equipment [Line Items]
Total cost	5,979		5,979
Laboratory equipment
Property, Plant and Equipment [Line Items]
Total cost	3,091		3,091
Computer equipment
Property, Plant and Equipment [Line Items]
Total cost	1,069		1,069
Office equipment and furniture
Property, Plant and Equipment [Line Items]
Total cost	$ 625		$ 625