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Commitments and Contingencies - Additional Information (Details) - USD ($)
 3 Months Ended 12 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Dec. 31, 2020
Loss Contingencies [Line Items]      
Contract termination commitment     $ 3,700,000
Commitment expenses recognized     $ 2,200,000
Rent expense $ 189,000 $ 176,000  
Redwood City, California      
Loss Contingencies [Line Items]      
Operating lease, term 2021-08    
Baltimore, Maryland      
Loss Contingencies [Line Items]      
Operating lease, term 2023-06    
Research and Development      
Loss Contingencies [Line Items]      
Contractual obligation $ 3,100,000    
Unpaid cancellation and other related costs $ 561,000    
Research and Development | Minimum      
Loss Contingencies [Line Items]      
Contractual obligation term 3 months    
Research and Development | Maximum      
Loss Contingencies [Line Items]      
Contractual obligation term 12 months    
Fixed Asset Purchase Agreements      
Loss Contingencies [Line Items]      
Write off of deposits $ 1,300,000    
Cancellation costs not yet been paid $ 900,000