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Stock-Based Compensation - Schedule of Assumptions Used to Determine Fair Value of Options Granted (Details)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Expected life (in years)   10 years
Expected dividend yield 0.00% 0.00%
Minimum [Member]    
Risk-free interest rate 2.82% 2.21%
Expected volatility 99.90% 90.40%
Expected life (in years) 8 years 6 months  
Maximum [Member]    
Risk-free interest rate 3.02% 1.32%
Expected volatility 102.10% 100.80%
Expected life (in years) 10 years