Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions (Details)

v3.19.1
Stockholders' Equity - Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions (Details)
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Equity [Abstract]    
Dividend yield 0.00% 0.00%
Risk-free interest rate, minimum 2.19% 2.86%
Risk-free interest rate, maximum 2.54% 2.94%
Expected volatility, minimum 105.20% 137.20%
Expected volatility, maximum 106.10% 137.30%
Expected life (in years) 5 years 10 years