CONVERTIBLE SENIOR NOTES - Components of Debt (Details) - Convertible Debt - USD ($) $ in Thousands	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018	Jan. 31, 2018
Debt Instrument [Line Items]
Convertible Debt Par Amount	$ 575,000	$ 575,000		$ 575,000
Debt Instrument, Unamortized Discount	(80,298)	(109,956)
Unamortized Debt Issuance Expense	(4,480)	(6,134)
Convertible Debt, Noncurrent	490,222	458,910
Debt Instrument, Convertible, Carrying Amount of Equity Component, Excluding Equity Issuance Costs	$ 148,598	$ 148,598
Debt Instrument, Interest Rate, Effective Percentage	6.62%
Debt Instrument, Convertible, Transaction Costs Attributable to Equity Component	$ 3,000		$ 3,000

Face (par) amount of debt instrument at time of issuance.

No definition available.

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- Definition

Debt Instrument, Convertible, Carrying Amount of Equity Component, Excluding Equity Issuance Costs

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Convertible, Transaction Costs Attributable to Equity Component

+ References

No definition available.

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- Definition

Carrying amount of long-term convertible debt as of the balance sheet date, net of the amount due in the next twelve months or greater than the normal operating cycle, if longer. The debt is convertible into another form of financial instrument, typically the entity's common stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6036836-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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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.

+ Details

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- Definition

Amount, after accumulated amortization, of debt discount.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28541-108399

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
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-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

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- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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