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Income Taxes (Details 4) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Reserves deducted from deferred income taxes, net:
Valuation allowance - Balance at beginning of year	$ 129,872	$ 130,498	$ 127,449
Valuation allowance - Additions charged to costs and expenses		16,017	3,049
Valuation allowance - Deductions	(53,852)	(16,643)
Valuation allowance - Balance at end of year	$ 76,020	$ 129,872	$ 130,498

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- References

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
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Amount of valuation allowance of deferred tax asset attributable to deductible temporary differences and carryforwards, classified as current.

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-Name Accounting Standards Codification
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Amount of increase in valuation and qualifying accounts and reserves from charge to cost and expense.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SX 210.12-09)
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Amount of decrease in valuation and qualifying accounts and reserves.

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