XML 46 R36.htm IDEA: XBRL DOCUMENT v3.21.1
Stockholders' Equity - Weighted-Average assumptions (Details) - $ / shares
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Weighted-average assumptions    
Expected term 6 years 3 months 6 years 3 months
Expected volatility 83.72% 84.30%
Risk-free interest rate 0.63% 1.59%
Expected dividend yield 0.00% 0.00%
2013 Equity Incentive and Inducement Plan    
Share-based Compensation Arrangement by Share-based Payment Award    
Weighted-average fair value of the options granted $ 2.70 $ 3.35