Income Taxes - Schedule of Change in Valuation Allowance (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012
Income Tax Disclosure [Abstract]
Valuation allowance - Balance at beginning of year	$ 167,328	$ 204,977	$ 206,669
Valuation allowance - Additions charged to costs and expenses		462	41,925
Valuation allowance - Deductions	(15,353)	(38,111)	(43,617)
Valuation allowance - Balance at end of year	$ 151,975	$ 167,328	$ 204,977

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319

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- Definition

Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, charged to costs and expenses.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 09

-Article 12

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- Definition

Total of the deductions in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, representing receivables written off as uncollectible and portions of the reserves utilized, respectively.

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