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Stock-Based Awards - Summary of Assumptions Used for Estimating the Fair Value of Stock Options Granted (Details) - Stock Options
6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Volatility, minimum 65.20% 66.90%
Volatility, maximum 67.10% 77.80%
Risk-free interest rate, minimum 0.40% 2.00%
Risk-free interest rate, maximum 1.70% 2.60%
Dividend yield 0.00% 0.00%
Minimum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected term (in years) 5 years 6 months 5 years 6 months
Maximum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected term (in years) 6 years 29 days 6 years 29 days