Plan Assets Held in Trust (Detail)	12 Months Ended
Jul. 31, 2015	Jul. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage	100.00%
Actual allocation percentage	100.00%	100.00%
Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage	60.00%
Actual allocation percentage	59.90%	60.90%
Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage	40.00%
Actual allocation percentage	40.10%	39.10%

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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- Definition

Target allocation of investments of this type to total plan assets presented on a weighted average basis.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 5

-Subparagraph (c)(i)

-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e2446-114920

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

-Publisher FASB

-Name Accounting Standards Codification

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-Section 50

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Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 5

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e2446-114920

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

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-Section 50

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-URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920

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