Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Interest expense	$ 7,824	$ 11,156	$ 14,300
Income tax expense (benefit)	29,235	20,093	(4,963)
Pre-tax amortization of intangible assets	$ 9,056	$ 12,103	$ 17,871