Convertible Senior Notes - Summary of Total Interest Expense Recognized Related To Convertible Senior Notes (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
0% Convertible Senior Notes Due 2026
Debt Instrument [Line Items]
Amortization of debt discount and transaction costs	$ 1,056
Total interest expense	1,056
0.125% Convertible Senior Notes Due 2024
Debt Instrument [Line Items]
Amortization of debt discount and transaction costs	4,639	$ 4,406
Total interest expense	4,780	4,547
0.125% Convertible Senior Notes Due 2024 \| 0.125% coupon
Debt Instrument [Line Items]
Interest expense	141	141
1.50% Convertible Senior Notes Due 2022
Debt Instrument [Line Items]
Amortization of debt discount and transaction costs	618	1,030
Total interest expense	724	1,375
1.50% Convertible Senior Notes Due 2022 \| 1.50% Coupon
Debt Instrument [Line Items]
Interest expense	$ 106	$ 345

Amount of amortization expense attributable to debt discount (premium) and debt issuance costs.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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