Convertible Senior Notes, Net - Summary of Note Terms (Details) - Convertible Debt	9 Months Ended
Sep. 30, 2020 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Debt Instrument [Line Items]
Principal Amount	$ 575,000,000
Conversion rate basis, principal amount	1,000
2022 Notes
Debt Instrument [Line Items]
Principal Amount	$ 345,000,000		$ 345,000,000.0
Coupon Rate	4.75%		4.75%
Effective Rate	5.60%
Conversion Rate	0.0502260
Remaining Period of Amortization	1 year 10 months 24 days
2023 Notes
Debt Instrument [Line Items]
Principal Amount	$ 230,000,000	$ 230,000,000.0
Coupon Rate	5.38%	5.375%
Effective Rate	6.16%
Conversion Rate	0.0487187
Remaining Period of Amortization	3 years 14 days

Debt Instrument, Convertible, Conversion Rate Basis, Principal Amount

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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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Remaining amortization period for discount on the liability component of convertible debt which may be settled in cash upon conversion, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Face (par) amount of debt instrument at time of issuance.

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- Definition

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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