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StockBased Compensation (Details 2) - Employee Stock Option
6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Expected dividend yield 0.00% 0.00%
Minimum Member    
Risk-free interest rate 0.63% 0.35%
Expected volatility 76.60% 73.30%
Expected life (years) 5 years 5 years 6 months
Maximum Member    
Risk-free interest rate 1.14% 1.66%
Expected volatility 76.90% 74.40%
Expected life (years) 6 years 29 days 6 years 1 month 13 days