Fair Value Measurements - Financial Assets and Liabilities Accounted for at Fair Value on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended					3 Months Ended										3 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Jul. 31, 2013	Oct. 31, 2013 Other Assets [Member]	Jul. 31, 2013 Other Assets [Member]	Oct. 31, 2013 Prepaid expenses and other current assets [Member]	Jul. 31, 2013 Prepaid expenses and other current assets [Member]	Oct. 31, 2013 Other current liabilities [Member]	Jul. 31, 2013 Other current liabilities [Member]	Oct. 31, 2013 Fair Value, Inputs, Level 1 [Member]	Jul. 31, 2013 Fair Value, Inputs, Level 1 [Member]	Oct. 31, 2013 Fair Value, Inputs, Level 1 [Member] Other Assets [Member]	Jul. 31, 2013 Fair Value, Inputs, Level 1 [Member] Other Assets [Member]	Oct. 31, 2013 Fair Value, Inputs, Level 2 [Member]	Jul. 31, 2013 Fair Value, Inputs, Level 2 [Member]	Oct. 31, 2013 Fair Value, Inputs, Level 2 [Member] Prepaid expenses and other current assets [Member]	Jul. 31, 2013 Fair Value, Inputs, Level 2 [Member] Prepaid expenses and other current assets [Member]	Oct. 31, 2013 Fair Value, Inputs, Level 2 [Member] Other current liabilities [Member]	Jul. 31, 2013 Fair Value, Inputs, Level 2 [Member] Other current liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities				$ 15,133	$ 14,975							$ 15,133	$ 14,975
Foreign exchange contracts	244	5,301				438	294	408	890							438	294	408	890
Total Assets	15,571		15,269							15,133	14,975			438	294
Total Liabilities	$ 408		$ 890											$ 408	$ 890