Components of Other Gains (Losses), Net (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2013	Jan. 31, 2012
Gain (Loss) on Investments [Line Items]
Foreign currency exchange gain (losses)	$ (1,034)	$ 798	$ (2,060)	$ 1,995
Gain (loss) on disposal of assets	(58)	80	(62)	105
Other, net	114	(53)	(177)	(48)
Other Operating Income (Expense), Net, Total	$ (978)	$ 825	$ (2,299)	$ 2,052