Annual report pursuant to Section 13 and 15(d)

Income Taxes - Narrative (Details)

v3.20.4
Income Taxes - Narrative (Details) - USD ($)
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Income Tax Examination [Line Items]    
Current federal and state income tax expense (benefit) $ 0 $ 0
Deferred federal and state income tax expense (benefit) 0 0
Increase (decrease) in valuation allowance 3,192,000 $ 3,899,000
Federal    
Income Tax Examination [Line Items]    
Operating loss carryforwards 164,296,000  
Federal | Research and development tax credit    
Income Tax Examination [Line Items]    
Operating loss carryforwards 1,943,000  
State    
Income Tax Examination [Line Items]    
Operating loss carryforwards 106,955,000  
State | Research and development tax credit    
Income Tax Examination [Line Items]    
Operating loss carryforwards 641,000  
Foreign    
Income Tax Examination [Line Items]    
Operating loss carryforwards 9,655,000  
Generated before 2018, expire 2027 | Federal    
Income Tax Examination [Line Items]    
Operating loss carryforwards 120,792,000  
Generated before 2018, carryforward indefinitely | Federal    
Income Tax Examination [Line Items]    
Operating loss carryforwards $ 43,503,000