Convertible Senior Notes - Schedule of Net Carrying Amount of the Liability Component of the Notes (Details) $ in Thousands	Apr. 30, 2020 USD ($)
2024 Notes
Debt Instrument [Line Items]
Principal	$ 90,001
Unamortized debt discount	(18,465)
Unamortized debt issuance costs	(1,475)
Net carrying amount	70,061
2026 Notes
Debt Instrument [Line Items]
Principal	1,150,000
Unamortized debt discount	(282,386)
Unamortized debt issuance costs	(14,577)
Net carrying amount	$ 853,037

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.

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Amount, after accumulated amortization, of debt discount.

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Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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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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