Long-Term Debt - Summary of Maturities of Borrowing Obligations (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Sep. 30, 2024
Debt Instrument [Line Items]
2025	$ 60,125
2028	210,000
Total before unamortized discount and issuance costs and current portion	270,125
Less: unamortized discount and issuance costs	(13,963)
Less: current portion of long-term debt	(59,954)	$ (87,094)
Total long-term debt	196,208	$ 194,812
2028 Notes
Debt Instrument [Line Items]
2028	122,500
Total before unamortized discount and issuance costs and current portion	122,500
Less: unamortized discount and issuance costs	(1,692)
Total long-term debt	120,808
2025 Modified Notes
Debt Instrument [Line Items]
2025	60,125
2028	87,500
Total before unamortized discount and issuance costs and current portion	147,625
Less: unamortized discount and issuance costs	(12,271)
Less: current portion of long-term debt	(59,954)
Total long-term debt	$ 75,400