Stock-Based Compensation Expense and Shareholders' Equity (Details Textual) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019	Jul. 31, 2019
Stockholders Equity and Stock Based Compensation (Additional Textual) [Abstract]
Common stock, shares authorized (in shares)	500,000,000		500,000,000		500,000,000
Common stock, par value (in dollars per share)	$ 0.0001		$ 0.0001		$ 0.0001
Shares issued (in shares)	83,167,042		83,167,042		82,140,883
Shares outstanding (in shares)	83,167,042		83,167,042		82,140,883
Additional percentage of shares reserved			5.00%
Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Period of time based Vesting	4 years		4 years
Share-based compensation expense	$ 2.3	$ 2.4	$ 9.5	$ 9.5
TSR PSUs
Class of Stock [Line Items]
Period of time based Vesting	3 years