XML 43 R31.htm IDEA: XBRL DOCUMENT v3.21.2
Stock-Based Compensation (Schedule of Weighted-Average Assumption Terms) (Details)
9 Months Ended
Sep. 30, 2021
$ / shares
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]  
Expected dividend yield
Minimum [Member]  
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]  
Exercise price $ 5.93
Market value $ 5.93
Expected term 5 years
Expected volatility 105.00%
Risk-free interest rate 0.98%
Maximum [Member]  
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]  
Exercise price $ 20.68
Market value $ 20.68
Expected term 6 years
Expected volatility 109.00%
Risk-free interest rate 1.09%