Net Changes in Operating Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010
Cash Flow Supplemental Disclosures [Line Items]
Accounts and notes receivable	$ (8,258)	$ (17,099)	$ (12,703)
Inventories	(4,765)	(16,821)	(7,435)
Other assets	2,525	2,578	(2,506)
Refundable income taxes	312	(315)	2,831
Accounts payable, trade	1,548	12,490	2,654
Accrued liabilities	3,948	4,078	2,489
Other liabilities	265	2,405	625
Advance payments and deferred revenue	5,471	(54)	1,535
Accrued income taxes	3,850	1,298	2,387
Net changes in operating assets and liabilities	$ 4,896	$ (11,440)	$ (10,123)

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The increase (decrease) during the reporting period of the sum of amounts due within one year (or one business cycle) from customers for the credit sale of goods and services; and from note holders for outstanding loans.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

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- Definition

The increase (decrease) during the reporting period in the aggregate amount of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business.

+ References

+ Details

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- Definition

The increase (decrease) during the period in the amount due for taxes based on the reporting entity's earnings or attributable to the entity's income earning process (business presence) within a given jurisdiction.

+ References

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- Definition

The increase (decrease) during the reporting period in the aggregate amount of expenses incurred but not yet paid.

+ References

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- Definition

The increase (decrease) during the reporting period in the amount of (a) prepayments by customers for goods or services to be provided at a later date, (b) the amount of customer money held in customer accounts, including security deposits, collateral for current or future transactions, initial payment of the cost of an acquisition or for the right to enter into a contract or agreement, (c) the increase (decrease) during the reporting period, excluding the portion taken into income, in the liability reflecting services yet to be performed by the reporting entity for which cash or other forms of consideration was received or recorded as a receivable, or (d) some combination of (a), (b), and (c).

+ References

No definition available.

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- Definition

The increase (decrease) during the reporting period in the amounts payable to taxing authorities for taxes that are based on the reporting entity's earnings, net of amounts receivable from taxing authorities for refunds of overpayments or recoveries of income taxes, and in deferred and other tax liabilities and assets.

+ References

No definition available.

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- Definition

The increase (decrease) during the reporting period in the aggregate value of all inventory held by the reporting entity, associated with underlying transactions that are classified as operating activities.

+ References

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- Definition

The increase (decrease) during the reporting period of all assets and liabilities used in operating activities.

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- Definition

The increase (decrease) during the reporting period in other assets used in operating activities not separately disclosed in the statement of cash flows. May include changes in other current assets, other noncurrent assets, or a combination of other current and noncurrent assets.

+ References

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The increase (decrease) during the reporting period in other liabilities used in operating activities not separately disclosed in the statement of cash flows. May include changes in other current liabilities, other noncurrent liabilities, or a combination of other current and noncurrent liabilities.

+ References

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