Unsecured Convertible Senior Notes - Future minimum payments (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Long-term Debt, Fiscal Year Maturity [Abstract]
Total future minimum payments under the convertible senior notes	$ 320,030
2023 and 2026 Convertible Senior Notes
Long-term Debt, Fiscal Year Maturity [Abstract]
2023	95,000
2026	225,030
Total future minimum payments under the convertible senior notes	$ 320,030

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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-Name Accounting Standards Codification
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-Section 50
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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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-Publisher FASB
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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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