Nature of the Business and Basis of Presentation (Details) - USD ($)
$ in Thousands
12 Months Ended
Mar. 18, 2021
Jul. 20, 2018
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Sale of Equity          
Net proceeds after deducting underwriting discounts and commissions     $ 188,000    
Net Loss     (196,547) $ (167,731) $ (163,458)
Accumulated deficit     (677,018) $ (480,471)  
Current cash and investments     $ 225,800    
Common stock          
Sale of Equity          
Shares issued (in shares)     6,896,552   1,449,309
Conversion of redeemable convertible preferred stock to common stock (in shares)   51,845,438      
IPO          
Sale of Equity          
Shares issued (in shares)   12,055,450      
Offering          
Sale of Equity          
Shares issued (in shares) 6,896,552        
Net proceeds after deducting underwriting discounts and commissions $ 187,200        
Overallotment          
Sale of Equity          
Shares issued (in shares)   1,572,450      
Net proceeds after deducting underwriting discounts and commissions   $ 254,300