Debt - Note Repurchases (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Dec. 31, 2022	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023	May 31, 2018	May 14, 2018	Jul. 05, 2017
Debt Instrument [Line Items]
(Gain) loss on extinguishment	$ 3,500	$ 0	$ 0	$ 3,545
2024 Convertible Notes | Notes Repurchases
Debt Instrument [Line Items]
Repurchased principal amount	109,400
Repurchased amount	117,500
2024 Convertible Notes | Senior Notes
Debt Instrument [Line Items]
Stated interest rate							2.875%
(Gain) loss on extinguishment		0	0	8,935
2025 Convertible Notes | Notes Repurchases
Debt Instrument [Line Items]
Repurchased principal amount	69,100
Repurchased amount	$ 62,900
2025 Convertible Notes | Senior Notes
Debt Instrument [Line Items]
Stated interest rate					2.375%	2.375%
(Gain) loss on extinguishment		$ 0	$ 0	$ (5,389)