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Equity Compensation Plans - Assumptions Of Black-Scholes Option Grant (Details)
9 Months Ended
Sep. 30, 2019
$ / shares
Share Based Payment Award Stock Options Valuation Assumptions [Line Items]  
Risk-free interest rate, minimum 1.90%
Risk-free interest rate, maximum 2.60%
Volatility, minimum 109.00%
Volatility, maximum 113.00%
Dividend yield 0.00%
Weighted average fair value $ 1.77
Minimum  
Share Based Payment Award Stock Options Valuation Assumptions [Line Items]  
Expected term (in years) 5 years 14 days
Maximum  
Share Based Payment Award Stock Options Valuation Assumptions [Line Items]  
Expected term (in years) 6 years 349 days