Derivative financial instruments - Outstanding Currency, Forward Exchange Contracts (Detail) - Foreign Currency Forward Contracts - USD ($) $ in Thousands	Jul. 31, 2022	Jul. 31, 2021
Sell
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	$ 168,410	$ 186,837
Sell | Euro
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	88,275	118,988
Sell | British pound
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	36,779	27,861
Sell | Japanese yen
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	16,688	15,939
Sell | Australian dollar
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	278	934
Sell | Hong Kong dollar
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	0	283
Sell | Singapore dollar
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	378	458
Sell | Others
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	26,012	22,374
Buy
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	642,295	627,421
Buy | Euro
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	333,285	337,817
Buy | British pound
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	78,942	86,778
Buy | Japanese yen
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	37,163	43,281
Buy | Australian dollar
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	9,426	10,462
Buy | Hong Kong dollar
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	67,341	37,556
Buy | Singapore dollar
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	18,025	18,448
Buy | Others
Derivative [Line Items]
Notional Amounts of foreign currency derivative contracts	$ 98,113	$ 93,079