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Convertible Senior Notes - Schedule of Net Carrying Amount of the Equity Component of the Notes (Details) - USD ($) $ in Thousands | Oct. 31, 2018 | Jul. 31, 2018
--- | --- | ---
Debt Instrument [Line Items] |  |
Debt discount for conversion option |  | $ 84,200
Convertible Debt |  |
Debt Instrument [Line Items] |  |
Unamortized debt issuance costs |  | (8,800)
Convertible Senior Notes, Equity Component | Convertible Debt |  |
Debt Instrument [Line Items] |  |
Debt discount for conversion option | $ 84,168 |
Unamortized debt issuance costs | (2,485) | $ (2,500)
Net carrying amount | $ 81,683 |

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- Definition The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870 + Details
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- Definition Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399 + Details
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