Other Income (Expense) - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
Component Of Other Expense Income Nonoperating [Line Items]
Foreign exchange gains (losses)	$ (1,546)	$ 668	$ (678)

Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6450189&loc=d3e30690-110894

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6450222&loc=d3e30840-110895

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 20

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6450189&loc=d3e30700-110894

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration