Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Change in Level 3 (Details)

v3.20.2
Fair Value Measurements - Change in Level 3 (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Loss on revaluation of warrants issued in connection with the June 2020, December 2019, May 2019, and December 2015 equity financings $ 8,574 $ (2,737) $ 6,055 $ (1,615)
Warrant Liability        
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Beginning balance     4,307  
Initial valuation of warrants in connection with June 2020 financing     2,650  
Loss on revaluation of warrants issued in connection with the June 2020, December 2019, May 2019, and December 2015 equity financings     6,055  
Gain on revaluation of contingent liability     0  
Reclassification of warrant liability to equity upon exercise of warrants     (651)  
Ending balance 12,361   12,361  
Contingent Success Fee Liability        
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]        
Beginning balance     6  
Initial valuation of warrants in connection with June 2020 financing     0  
Loss on revaluation of warrants issued in connection with the June 2020, December 2019, May 2019, and December 2015 equity financings     0  
Gain on revaluation of contingent liability     (6)  
Reclassification of warrant liability to equity upon exercise of warrants     0  
Ending balance $ 0   $ 0