Convertible Senior Notes and Capped Call Transactions - Narrative (Details)		3 Months Ended
May 11, 2020 USD ($)	Mar. 31, 2021 USD ($) tradingDay $ / shares
Debt Instrument [Line Items]
Cap price \| $ / shares		$ 47.24
Percentage premium over the last reported sale price of company common stock used to calculate cap price		100.00%
2025 Senior Notes
Debt Instrument [Line Items]
Equity component, net of discount and issuance costs		$ 30,794,000
Fair value of the notes		$ 452,286,000
Convertible Debt
Debt Instrument [Line Items]
Payments for capped calls	$ 29,348,000
Convertible Debt \| 2025 Senior Notes
Debt Instrument [Line Items]
Principal amount excluding purchasers' option	220,000,000
Additional amount included in principal from exercised options	33,000,000
Proceeds from follow-on offering, net	$ 245,158,000
Interest rate, stated percentage	1.25%
Debt instrument, convertible, conversion ratio		32.5668
Initial conversion price (in dollars per share) \| $ / shares		$ 30.71
Repurchase of notes percentage		100.00%
Equity component, net of discount and issuance costs		$ 31,779,000
Interest rate, effective percentage		4.51%
Debt issuance costs of liability component		$ 6,857,000
Convertible Debt \| 2025 Senior Notes \| Additional paid-in capital
Debt Instrument [Line Items]
Debt issuance costs of equity component		$ 985,000
Convertible Debt \| 2025 Senior Notes \| Debt Conversion, Option One
Debt Instrument [Line Items]
Threshold trading days (in trading days) \| tradingDay		20
Threshold consecutive trading days \| tradingDay		30
Threshold percentage of conversion price		130.00%
Convertible Debt \| 2025 Senior Notes \| Debt Conversion, Option Two
Debt Instrument [Line Items]
Threshold consecutive trading days \| tradingDay		5
Threshold percentage of conversion price		98.00%
Threshold consecutive business days \| tradingDay		5

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

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The price per share of the conversion feature embedded in the debt instrument.

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Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

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Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instrument must exceed threshold percentage for specified number of trading days to trigger conversion feature.

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Minimum percentage of common stock price to conversion price of convertible debt instruments to determine eligibility of conversion.

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Threshold number of specified trading days that common stock price to conversion price of convertible debt instruments must exceed threshold percentage within a specified consecutive trading period to trigger conversion feature.

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

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Contractual interest rate for funds borrowed, under the debt agreement.

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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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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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The cash inflow from the issuance of a long-term debt instrument which can be exchanged for a specified amount of another security, typically the entity's common stock, at the option of the issuer or the holder.

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Debt Instrument, Additional Amount Included in Principal from Exercised Options

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Debt Instrument, Convertible, Debt Issuance Costs Of Equity Component

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Debt Instrument, Convertible, Debt Issuance Costs Of Liability Component

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Debt Instrument, Convertible, Threshold Consecutive Business Days

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Debt Instrument, Face Amount Excluding Purchasers’ Option

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Debt Instrument Repurchase Price As Percentage of Principal Amount Plus Accrued and Unpaid Interest In Event Of Change

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Derivative, Initial Cap Price

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Derivative, Percentage Premium Over the Last Reported Sale Price of Company Common Stock

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Payments for Capped Calls

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