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Fair Value Measurements (Details 1) - Level 3 [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2019	Jan. 31, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	$ 2,816	$ 6,300		$ 6,300
Transfer into Level 3 from adoption of change in accounting for equity investments			2,794
Total losses recognized in "Other income (expense), net"	(71)		(49)
Balance, end of period	2,745	6,300	2,745	6,300
Change in unrealized gains or losses for the period included in earnings for assets held at the end of the period	$ (71)		$ (49)

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- Definition

Amount of change in unrealized gains or losses included in earnings for assets held at end of period.

+ References

No definition available.

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- Definition

Amount of fair value measurement with unobservable inputs reconciliation recurring basis asset transfers into level three from adoption of accounting change.

+ References

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- Definition

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.

+ References

No definition available.

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- Definition

Amount of gain (loss) recognized in the income statement for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

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- Definition

Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

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