XML 33 R52.htm IDEA: XBRL DOCUMENT v3.20.1
Stock-Based Compensation (Details 2)
12 Months Ended
Dec. 31, 2018
Summary of assumptions used to value stock options granted to employees, directors and consultants  
Annual dividend yield
Expected life (years) 1 year 6 months
Risk-free interest rate 2.19%
Expected volatility 71.12%