Convertible Senior Notes, Net - Schedule of Liability and Equity Component of 2023 Notes (Details) - Senior Notes $ in Thousands	Apr. 30, 2020 USD ($)
Convertible Senior Notes Due 2023
Liability component:
Principal	$ 120,586
Less: unamortized debt issuance costs and debt discount	(18,388)
Net carrying amount	102,198
Convertible Senior Notes Due 2025
Liability component:
Principal	1,060,000
Less: unamortized debt issuance costs and debt discount	(214,138)
Net carrying amount	845,862
Additional Paid-in Capital \| Convertible Senior Notes Due 2023
Equity component:
Equity component	27,949
Less: issuance costs	(811)
Carrying amount of the equity component	27,138
Additional Paid-in Capital \| Convertible Senior Notes Due 2025
Equity component:
Equity component	221,387
Less: issuance costs	(4,040)
Carrying amount of the equity component	$ 217,347

Debt Instrument, Convertible, Carrying Amount of Equity Component, Net

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- Definition

Debt Instrument, Convertible, Equity Component, Unamortized Discount Issuance Costs

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Equity Component [Abstract]

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Liability Component [Abstract]

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

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The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion.

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Amount of unamortized debt discount (premium) and debt issuance costs.

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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