Derivatives and Hedging Activities - Additional Information (Detail) $ in Thousands, £ in Millions	3 Months Ended
	Oct. 31, 2017 USD ($)	Oct. 31, 2016 USD ($)	Oct. 31, 2017 GBP (£)	Jul. 31, 2017 USD ($)
Summary
Derivative maturity	18 months
Derivative, Notional Amount	$ 25,638			$ 81,195
Summary of Cash Flow Hedge Activity
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	710	$ 58
Cash Flow Hedge Gain (Loss) Reclassified from OCI to Earnings	24	405
Total Outstanding Forward Foreign Exchange Contracts	22,538
Summary of Derivative Instruments Not Designated as Hedging Instruments
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	$ 22	$ (1,733)
Senior Unsecured Notes [Member]
Summary of Net Investment Hedge Activity
Net investment hedges to hedge portions of net investment | £			£ 45