Revenue - Summary of Deferred Revenue Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Movement in Deferred Revenue [Roll Forward]
Balance at beginning of period	$ 918	$ 1,212
Cash Received from NIH	1,000	2,400
Recognized as revenue	(1,563)	(2,694)
Balance at end of period	355	918
NIH Grant
Movement in Deferred Revenue [Roll Forward]
Balance at beginning of period	918	568
Cash Received from NIH	1,000	2,400
Recognized as revenue	(1,563)	(2,050)
Balance at end of period	355	918
BED
Movement in Deferred Revenue [Roll Forward]
Balance at beginning of period	0	644
Cash Received from NIH	0	0
Recognized as revenue	0	(644)
Balance at end of period	$ 0	$ 0