Long-Term Debt - Summary of Maturities of Borrowing Obligations (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Debt Instrument [Line Items]
2022	$ 3,125
2023	10,938
2024	12,500
2025	262,500
Total before unamortized discount and issuance costs and current portion	289,063
Less: unamortized discount and issuance costs	(18,250)
Less: current portion of long-term debt	(7,813)	$ (6,250)
Total long-term debt	263,000	$ 265,093
Senior Facilities
Debt Instrument [Line Items]
2022	3,125
2023	10,938
2024	12,500
2025	87,500
Total before unamortized discount and issuance costs and current portion	114,063
Less: unamortized discount and issuance costs	(1,761)
Less: current portion of long-term debt	(7,813)
Total long-term debt	104,489
Convertible Senior Notes
Debt Instrument [Line Items]
2025	175,000
Total before unamortized discount and issuance costs and current portion	175,000
Less: unamortized discount and issuance costs	(16,489)
Total long-term debt	$ 158,511

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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