Debt (Tables)

12 Months Ended

Sep. 30, 2022

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments

The following tables present our debt instruments outstanding, contractual maturities and interest expense:

	September 30, 2022						September 30, 2021
(in thousands)	Gross Amount		Debt Issuance Costs		Carrying Amount		Gross Amount		Debt Discount and Issuance Costs		Carrying Amount
2024 Convertible Notes	$	143,750	$	(1,175)	$	142,575	$	143,750	$	(20,207)	$	123,543
2025 Convertible Notes	172,500		(2,172)		170,328		172,500		(31,857)		140,643
Total long-term debt	$	316,250	$	(3,347)	$	312,903	$	316,250	$	(52,064)	$	264,186

Schedule of Maturities of Debt

	Schedule of Contractual Maturities
(in thousands)	Total		Less Than 1 Year		1 - 3 Years		3 - 5 Years
2024 Convertible Notes	$	143,750	$	—	$	143,750	$	—
2025 Convertible Notes	172,500		—		172,500		—
Total	$	316,250	$	—	$	316,250	$	—

Schedule of Interest Expense

	Fiscal Year Ended September 30,
(in thousands)	2022		2021		2020
2024 Convertible Notes:
Contractual interest expense	$	4,133	$	4,133	$	4,133
Amortization of deferred financing costs	635		446		446
Amortization of debt discount	—		5,903		5,437
Total interest expense	$	4,768	$	10,482	$	10,016
2025 Convertible Notes:
Contractual interest expense	$	4,097	$	4,097	$	4,097
Amortization of deferred financing costs	797		560		561
Amortization of debt discount	—		6,919		6,393
Total interest expense	$	4,894	$	11,576	$	11,051