Borrowings - Encore Convertible Notes and Exchangeable Notes (Details) $ / shares in Units, $ in Thousands	3 Months Ended
Mar. 31, 2021 USD ($) $ / shares	Dec. 31, 2020 USD ($)
Debt Instrument [Line Items]
Debt issued \| $	$ 422,500	$ 583,500
Convertible Notes \| 2021 Convertible Notes
Debt Instrument [Line Items]
Debt issued \| $	$ 0	161,000
Stated interest rate (as a percent)	2.875%
Convertible Notes \| 2022 Convertible Notes
Debt Instrument [Line Items]
Debt issued \| $	$ 150,000	150,000
Stated interest rate (as a percent)	3.25%
Initial conversion price (USD per share)	$ 45.57
Closing stock price at date of issuance (in dollars per share)	$ 35.05
Conversion rate (shares per $1,000 principal amount)	0.0219467
Convertible Notes \| 2025 Convertible Notes
Debt Instrument [Line Items]
Debt issued \| $	$ 100,000	100,000
Stated interest rate (as a percent)	3.25%
Initial conversion price (USD per share)	$ 40.00
Closing stock price at date of issuance (in dollars per share)	$ 32.00
Conversion rate (shares per $1,000 principal amount)	0.025
Exchangeable Notes \| 2023 Exchangeable Notes
Debt Instrument [Line Items]
Debt issued \| $	$ 172,500	$ 172,500
Stated interest rate (as a percent)	4.50%
Initial conversion price (USD per share)	$ 44.62
Closing stock price at date of issuance (in dollars per share)	$ 36.45
Conversion rate (shares per $1,000 principal amount)	0.022409

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

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- Definition

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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- Definition

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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- Definition

Price of a single share of a number of saleable stocks of a company.

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