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Net Income (Loss) Per Share (Details 2) - $ / shares	3 Months Ended		9 Months Ended
Net Income (Loss) Per Share (Details 2) - $ / shares	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019
Senior Notes \| Convertible Debt \| On or after October 15, 2024
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Conversion price (in dollars per share)	$ 113.75		$ 113.75
Stock options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from EPS (in shares)	146,617	334,909	180,243	413,145
Stock awards
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities excluded from EPS (in shares)	1,751,083	2,638,973	2,589,517	2,215,378