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EQUITY AWARD PLANS - ESPP (Details) - Employee Stock Purchase Plan
9 Months Ended
Apr. 30, 2020
Apr. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected term (in years) 11 months 1 day 10 months 2 days
Risk-free interest rate 0.10% 2.50%
Volatility 73.40% 69.00%
Dividend yield 0.00% 0.00%