Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Schedule of Assumptions Used to Calculate Fair Value of Stock Based Compensation (Details)

v3.19.3.a.u2
Stock-Based Compensation - Schedule of Assumptions Used to Calculate Fair Value of Stock Based Compensation (Details)
3 Months Ended
Oct. 31, 2019
Oct. 31, 2018
Risk-free interest rate, minimum 1.35% 2.68%
Risk-free interest rate, maximum 1.57% 3.08%
Volatility, minimum 80.93% 72.88%
Volatility, maximum 83.66% 81.80%
Dividend yield 0.00% 0.00%
Minimum [Member]    
Expected term (years) 5 years 5 years
Maximum [Member]    
Expected term (years) 6 years 6 months 6 years 6 months