Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Total property and equipment–at cost	$ 5,975	$ 7,061
Less: Accumulated depreciation	(4,797)	(5,935)
Property and equipment, net	1,178	1,126
Equipment
Property Plant And Equipment [Line Items]
Total property and equipment–at cost	5,389	5,356
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment–at cost	22	629
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment–at cost	200	896
Software
Property Plant And Equipment [Line Items]
Total property and equipment–at cost	$ 364	$ 180