Registration statement for securities of certain foreign private issuers

Share-Based Payment Transactions (Details 2)

v3.19.3.a.u2
Share-Based Payment Transactions (Details 2) - $ / shares
 1 Months Ended 12 Months Ended
Mar. 11, 2019
Jan. 31, 2019
Dec. 31, 2017
Dec. 31, 2016
Statement Line Items [Line Items]        
Risk-free interest rate 2.17% 2.40%    
Expected volatility 65.63% 75.86%    
Binomial option pricing model [Member]        
Statement Line Items [Line Items]        
Dividend yield     0.00% 0.00%
Contractual life (In years)     10 years 10 years
Early Exercise Multiple (Suboptimal Factor)     $ 2.5 $ 2.5
Binomial option pricing model [Member] | Bottom of range [Member]        
Statement Line Items [Line Items]        
Risk-free interest rate     1.89% 2.01%
Expected volatility     74.40% 77.84%
Exercise price     $ 0.72 $ 1.12
Binomial option pricing model [Member] | Top of range [Member]        
Statement Line Items [Line Items]        
Risk-free interest rate     2.31% 2.02%
Expected volatility     77.64% 78.22%
Exercise price     $ 0.98 $ 1.39