Annual report pursuant to Section 13 and 15(d)

Stock-based Compensation - Schedule of Share Based Payment Assumptions (Details)

v3.19.1
Stock-based Compensation - Schedule of Share Based Payment Assumptions (Details)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]    
Volatility, minimum 105.85% 67.80%
Volatility, maximum 111.31% 109.63%
Risk-free interest rate, minimum 2.29% 1.89%
Risk-free interest rate, maximum 3.08% 2.37%
Dividend yield 0.00% 0.00%
Expected life 6 years 6 years