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Stock Based Compensation - Summary of Weighted Average Assumptions Used in Valuing Plans (Details) - $ / shares
9 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]    
Fair value at grant date $ 0.98 $ 4.44
Expected volatility 142.10% 86.70%
Risk-free interest rate 0.70% 2.30%
Expected holding period, in years 6 years 1 month 6 days 5 years 8 months 12 days
Dividend yield