Acquisitions - Additional Information (Detail) - USD ($)	12 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Proceeds from Divestiture of Businesses		$ 19,141,000
Gain (Loss) on Disposition of Business	$ 0	$ (4,666,000)	$ 0