Variable Interest Entity - Schedule of Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Sep. 30, 2023
Variable Interest Entity [Line Items]
Restricted cash and cash equivalents	$ 1,272	$ 3,844
Other current assets	428,105	292,036
Securitized intangible asset, net	87,279	92,202
Current maturities of securitized long-term debt	8,001	9,922
Securitized long-term debt	81,261	85,078
Variable Interest Entity, Primary Beneficiary | AEK
Variable Interest Entity [Line Items]
Restricted cash and cash equivalents	1,272	3,844
Other current assets	2	11
Securitized intangible asset, net	87,279	92,202
Accrued interest	383	1,374
Current maturities of securitized long-term debt	8,001	9,922
Securitized long-term debt	$ 81,261	$ 85,078