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Summary of Significant Accounting Policies - Schedule of Weighted-Average Assumptions (Details)
3 Months Ended 9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected dividend yield     0.00%  
Stock options        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expected common stock price volatility 113.00% 117.00% 113.00% 117.00%
Risk-free interest rate, minimum 0.68% 0.22% 0.31% 0.22%
Risk-free interest rate, maximum 0.84% 0.26% 0.96% 1.34%
Expected term of options (years) 5 years 2 months 12 days 4 years 9 months 18 days 5 years 2 months 12 days 4 years 7 months 6 days
Expected dividend yield 0.00% 0.00% 0.00% 0.00%