Borrowings - Interest Expense of Debt (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Debt Instrument [Line Items]
Amortization of debt discount on the Notes			$ 1,364	$ 1,289
3.50% Convertible Senior Notes due October 1, 2024 \| Notes
Debt Instrument [Line Items]
Interest expense on the Notes	$ 1,312	$ 1,312	2,625	2,625
Amortization of debt discount on the Notes	$ 691	$ 654	$ 1,364	$ 1,289

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

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Name:	us-gaap_InterestExpenseDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration