Convertible Senior Notes - Interest Costs Recognized on 2026 Notes (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Debt Instrument [Line Items]
Total interest expense recognized	$ 2,040	$ 1,319	$ 4,048	$ 1,319
Convertible Debt \| 2026 Notes
Debt Instrument [Line Items]
Contractual interest expense	302	172	595	172
Amortization of debt discount and issuance costs	1,738	1,147	3,453	1,147
Total interest expense recognized	$ 2,040	$ 1,319	$ 4,048	$ 1,319

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

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration