Schedule of Aggregate Intrinsic Value of Options (Detail) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
Stockholders' Equity
Aggregate intrinsic value of options outstanding and expected to vest	$ 2,399	$ 966	$ 647
Aggregate intrinsic value of options exercisable	$ 2,399	$ 738	$ 647

Amount of difference between fair value of the underlying shares reserved for issuance and exercise prices of fully vested and expected to vest options outstanding.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph d(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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