XML 45 R35.htm IDEA: XBRL DOCUMENT v3.20.2
Stockholders' Equity - Weighted-Average assumptions (Details) - $ / shares
6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Weighted-average assumptions    
Expected term 6 years 3 months 6 years 3 months
Expected volatility 84.39% 71.14%
Risk-free interest rate 1.45% 2.55%
Expected dividend yield 0.00% 0.00%
2013 Equity Incentive Plan    
Share-based Compensation Arrangement by Share-based Payment Award    
Weighted-average fair value of the options granted $ 3.19 $ 7.20