Indebtedness - Schedule of Interest Expense Recognized (Details) - 2027 Notes - 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]
Contractual interest expense	$ 2,472	$ 1,139	$ 4,972	$ 1,139
Amortization of debt discount	1,589	642	3,107	642
Amortization of debt issuance cost	8	3	16	3
Total interest expense related to the 2027 Notes	$ 4,069	$ 1,784	$ 8,095	$ 1,784

Contractual interest expense.

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- Definition

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

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Amount of amortization expense attributable to debt issuance costs.

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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

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

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