Debt - Schedule of Net Carrying Amount of the Liability Component of the Notes (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	May 31, 2018
Debt Instrument [Line Items]
Principal	$ 258,749
Convertible debt \| Convertible Senior Notes
Debt Instrument [Line Items]
Principal	258,749	$ 258,750
Unamortized debt discount	(41,849)	(44,881)
Unamortized issuance costs	(3,976)	(4,265)	$ (6,000)
Total debt, net carrying value	$ 212,924	$ 209,604

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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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.

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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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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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-Paragraph 4
-Subparagraph (b)(3)
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