Annual report pursuant to Section 13 and 15(d)

Loan and Security Agreement - Additional Information (Details)

v3.20.1
Loan and Security Agreement - Additional Information (Details)
1 Months Ended 12 Months Ended
Feb. 28, 2020
USD ($)
Installment
shares
Aug. 31, 2017
USD ($)
Installment
Dec. 31, 2019
USD ($)
Installment
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Oct. 01, 2018
shares
Jul. 31, 2018
USD ($)
Debt Instrument [Line Items]              
Interest expense, debt     $ 1,100,000 $ 1,600,000 $ 600,000    
Repayment of debt     5,000,000        
Debt—non-current     8,876,000 10,000,000      
Debt—current     1,000,000 4,724,000      
Series E Redeemable Convertible Preferred Stock              
Debt Instrument [Line Items]              
Warrant to purchase stock | shares           46,359  
Two Thousand Seventeen Warrants              
Debt Instrument [Line Items]              
Estimated fair value portion of preferred stock             $ 300,000
Two Thousand Seventeen Warrants | Series E Redeemable Convertible Preferred Stock              
Debt Instrument [Line Items]              
Warrant to purchase stock | shares           46,359  
August 2017 Loan              
Debt Instrument [Line Items]              
Interest payable   $ 600,000 $ 400,000        
Average interest rate     8.72%        
Final payment fee percentage   3.83%          
Accretion of debt discount     $ 200,000 $ 200,000 $ 100,000    
August 2017 Loan | Floating Rate              
Debt Instrument [Line Items]              
Interest charges on loan   7.39%          
August 2017 Loan | LIBOR              
Debt Instrument [Line Items]              
Interest charges on loan   6.40%          
Description of interest charges on loan     the sum of the 30-day U.S. Dollar London Interbank Offered Rate (“LIBOR”) plus 6.40%.        
Loan and Security Agreement | Oxford Finance LLC and Silicon Valley Bank | Subsequent Event              
Debt Instrument [Line Items]              
Warrant to purchase stock | shares 81,257            
Loan and Security Agreement | Oxford Finance LLC and Silicon Valley Bank | August 2017 Loan              
Debt Instrument [Line Items]              
Borrowed amount   $ 15,000,000.0          
Loan and Security Agreement | Oxford Finance LLC and Silicon Valley Bank | August 2017 Loan | March 2019              
Debt Instrument [Line Items]              
Number of monthly installments | Installment   30          
Payment terms, description     The loan is due in 30 monthly installments from March 2019 through its repayment in August 2021, with interest-only monthly payments until March 2019. The Company commenced repayment of the loan in March 2019.        
Repayment installment, start date, month and year   2019-03          
Repayment installment, end date, month and year   2021-08          
Frequency of interest-only payments     monthly payments        
Interest-only payments, maturity month and year   2019-03          
Loan and Security Agreement | Oxford Finance LLC and Silicon Valley Bank | Term Loans              
Debt Instrument [Line Items]              
Payment terms, description     The Term Loans mature on March 1, 2024 (the “Maturity Date”) and will be interest-only through March 1, 2022, followed by 24 equal monthly payments of principal and interest.        
Description of interest charges on loan     The Term Loans will bear interest at a floating per annum rate equal to the greater of (i) 8.07% or (ii) the sum of (a) the greater of (1) the thirty (30) day U.S. LIBOR rate reported in the Wall Street Journal on the last business day of the month that immediately precedes the month in which the interest will accrue or (2) 1.67%, plus (b) 6.40%        
Loan and Security Agreement | Oxford Finance LLC and Silicon Valley Bank | Term Loans | Subsequent Event              
Debt Instrument [Line Items]              
Number of monthly installments | Installment 24            
Final payment fee percentage 3.83%            
Debt instrument, maturity date Mar. 01, 2024            
Interest-only payments, maturity date Mar. 01, 2022            
Loan and Security Agreement | Oxford Finance LLC and Silicon Valley Bank | Term Loans | Floating Rate | Subsequent Event              
Debt Instrument [Line Items]              
Interest charges on loan 8.07%            
Loan and Security Agreement | Oxford Finance LLC and Silicon Valley Bank | Term Loans | LIBOR | Subsequent Event              
Debt Instrument [Line Items]              
Interest charges on loan 6.40%            
Loan Agreement              
Debt Instrument [Line Items]              
Debt outstanding amount     $ 9,900,000        
Debt—non-current     8,900,000        
Debt—current     $ 1,000,000.0        
Loan Agreement | Subsequent Event              
Debt Instrument [Line Items]              
Gross proceeds on loan $ 25,000,000            
Loan Agreement | August 2017 Loan | Subsequent Event              
Debt Instrument [Line Items]              
Repayment of debt $ 9,600,000            
Loan Agreement | Term Loans              
Debt Instrument [Line Items]              
Number of monthly installments | Installment     24        
Payment terms, description     The Loan and Security Agreement matures on March 1, 2024 and will be interest-only through March 1, 2022, followed by 24 equal monthly payments of principal and interest.        
Debt instrument, maturity date     Mar. 01, 2024        
Interest-only payments, maturity date     Mar. 01, 2022