Notes Payable - Convertible Senior Notes - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Interest Expense
Contractual interest expense	$ 1,691	$ 1,804	$ 3,495	$ 3,607
Amortization of debt issuance costs	516	412	1,053	811
Amortization of debt discount		5,516		10,940
Total interest expense	$ 2,207	$ 7,732	$ 4,548	$ 15,358

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

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