Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Options Other Info (Details)

v3.19.3
Stockholders' Equity - Options Other Info (Details) - USD ($)
$ / shares in Units, $ in Millions
9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Options outstanding    
Intrinsic value of options exercisable $ 0.1  
Offering price $ 0.97  
Exercisable at the end of the period (in dollars per share) $ 4.41  
Employee Stock Option    
Options outstanding    
Unrecognized compensation expense $ 3.5  
Weighted average remaining period for recognition of unrecognized compensation expense 1 year 11 months 19 days  
Per-share weighted-average grant date fair value of options granted (in dollars per share) $ 0.70 $ 1.18
Employee Stock Option | Weighted-average    
Weighted-average assumptions:    
Expected term of options (in years) 6 years 1 month 6 days 5 years 9 months 18 days
Risk-free interest rate (as a percent) 1.90% 2.70%
Expected volatility (as a percent) 71.90% 74.90%
Dividend yield (as a percent) 0.00% 0.00%