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

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

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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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Amount, after accumulated amortization, of debt discount (premium).

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Amount, after 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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Debt - Convertible Senior Notes (Details) $ in Thousands	3 Months Ended
Debt - Convertible Senior Notes (Details) $ in Thousands	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Oct. 20, 2020 USD ($)	Jul. 23, 2018 USD ($)
1.75% Convertible Senior Notes due 2023
Debt Instrument [Line Items]
Aggregate Principal Amount	$ 23,777
Net Carrying Amount	$ 23,428	$ 22,482
1.75% Convertible Senior Notes due 2023 \| Senior Notes
Debt Instrument [Line Items]
Stated Cash Interest Rate	1.75%
Effective Interest Rate	2.45%
Conversion Rate	32.7332
Aggregate Principal Amount	$ 23,777	25,626		$ 143,750
Unamortized Debt Discount	0	2,776
Unamortized Debt Issuance Costs	349	368
Net Carrying Amount	23,428	22,482
0% Convertible Senior Notes due 2025
Debt Instrument [Line Items]
Aggregate Principal Amount	661,250
Net Carrying Amount	$ 648,713	488,268
0% Convertible Senior Notes due 2025 \| Senior Notes
Debt Instrument [Line Items]
Effective Interest Rate	0.42%
Conversion Rate	13.7920
Aggregate Principal Amount	$ 661,250	661,250	$ 661,250
Unamortized Debt Discount	0	163,077
Unamortized Debt Issuance Costs	12,537	9,905
Net Carrying Amount	648,713	488,268
0.5% Convertible Senior Notes Due 2027
Debt Instrument [Line Items]
Aggregate Principal Amount	500,000
Net Carrying Amount	$ 488,261	$ 0
0.5% Convertible Senior Notes Due 2027 \| Senior Notes
Debt Instrument [Line Items]
Stated Cash Interest Rate	0.50%
Effective Interest Rate	0.91%
Conversion Rate	10.6920
Aggregate Principal Amount	$ 500,000
Unamortized Debt Discount	0
Unamortized Debt Issuance Costs	11,739
Net Carrying Amount	$ 488,261