Financial Instruments - Schedule of Derivative Instruments in Statement of Financial Position, Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Sep. 30, 2024
Derivatives Fair Value [Line Items]
Gross/net financial instruments, assets	$ 120,951	$ 96,288
Gross/net financial instruments, liabilities	(4,063)	(7,637)
Designated As Hedges:
Derivatives Fair Value [Line Items]
Gross/net financial instruments, assets	117,154	91,981
Gross/net financial instruments, liabilities	0	0
Designated As Hedges: | Interest rate contracts
Derivatives Fair Value [Line Items]
Gross/net financial instruments, assets	117,154	91,981
Gross/net financial instruments, liabilities	0	0
Not Designated As Hedges:
Derivatives Fair Value [Line Items]
Gross/net financial instruments, assets	3,797	4,307
Gross/net financial instruments, liabilities	(4,063)	(7,637)
Not Designated As Hedges: | Other current assets | Commodity contracts
Derivatives Fair Value [Line Items]
Gross/net financial instruments, assets	2,459	2,091
Not Designated As Hedges: | Other current liabilities | Commodity contracts
Derivatives Fair Value [Line Items]
Gross/net financial instruments, liabilities	(4,063)	(7,324)
Not Designated As Hedges: | Deferred charges and other assets | Commodity contracts
Derivatives Fair Value [Line Items]
Gross/net financial instruments, assets	1,338	2,216
Not Designated As Hedges: | Deferred credits and other liabilities | Commodity contracts
Derivatives Fair Value [Line Items]
Gross/net financial instruments, liabilities	$ 0	$ (313)