Long-Term Debt - Summary of Maturities of Borrowing Obligations (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Sep. 30, 2021
Debt Instrument [Line Items]
2022	$ 1,562
2023	10,938
2024	12,500
2025	262,500
Total before unamortized discount and issuance costs and current portion	287,500
Less: unamortized discount and issuance costs	(16,923)
Less: current portion of long-term debt	(9,375)	$ (6,250)
Total long-term debt	261,202	$ 265,093
Senior Facilities
Debt Instrument [Line Items]
2022	1,562
2023	10,938
2024	12,500
2025	87,500
Total before unamortized discount and issuance costs and current portion	112,500
Less: unamortized discount and issuance costs	(1,614)
Less: current portion of long-term debt	(9,375)
Total long-term debt	101,511
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	(15,309)
Total long-term debt	$ 159,691

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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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount, excluding unamortized premium (discount) and debt issuance cost, of long-term debt classified as noncurrent. Excludes lease obligation.

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