Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurement - Schedule of changes in level 3 liabilities (Details)

v3.21.2
Fair Value Measurement - Schedule of changes in level 3 liabilities (Details) - USD ($)
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Warrants to purchase common stock          
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]          
Changes in fair value of liability     $ (675,000)   $ 0
Level 3 | Fair Value, Recurring          
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]          
Balance, beginning of the year     286,000 $ 286,000 286,000
VCIP/OBIP liability transferred out of Level 3     (286,000)   0
Changes in fair value of liability   $ 0   $ 0  
Balance, end of period $ 1,333,000   1,333,000   286,000
Level 3 | Fair Value, Recurring | Warrants to purchase common stock          
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]          
Closing-date fair value of warrant liability     2,008,000   $ 0
Changes in fair value of liability $ (300,000)   $ (700,000)