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Financial Instruments - Schedule of Derivative Instruments in Statement of Financial Position, Fair Value (Details) - USD ($) $ in Thousands | Mar. 31, 2023 | Sep. 30, 2022
--- | --- | ---
Derivatives Fair Value [Line Items] |  |
Net financial instruments, assets | $ 347,941 | $ 381,991
Net financial instruments, liabilities | (11,951) | (4,129)
Designated As Hedges: |  |
Derivatives Fair Value [Line Items] |  |
Gross financial instruments, assets | 345,967 | 355,075
Gross financial instruments, liabilities | (272) | 0
Designated As Hedges: | Other current assets | Interest rate contracts |  |
Derivatives Fair Value [Line Items] |  |
Gross financial instruments, assets | 95,735 |
Designated As Hedges: | Other current liabilities | Interest rate contracts |  |
Derivatives Fair Value [Line Items] |  |
Gross financial instruments, liabilities | (272) |
Designated As Hedges: | Deferred charges and other assets | Interest rate contracts |  |
Derivatives Fair Value [Line Items] |  |
Gross financial instruments, assets | 250,232 | 355,075
Designated As Hedges: | Deferred credits and other liabilities | Interest rate contracts |  |
Derivatives Fair Value [Line Items] |  |
Gross financial instruments, liabilities | 0 | 0
Not Designated As Hedges: |  |
Derivatives Fair Value [Line Items] |  |
Gross financial instruments, assets | 1,974 | 26,916
Gross financial instruments, liabilities | (11,679) | (4,129)
Not Designated As Hedges: | Other current assets | Commodity contracts |  |
Derivatives Fair Value [Line Items] |  |
Gross financial instruments, assets | 1,974 | 26,207
Not Designated As Hedges: | Other current liabilities | Commodity contracts |  |
Derivatives Fair Value [Line Items] |  |
Gross financial instruments, liabilities | $ (11,679) | (3,000)
Not Designated As Hedges: | Deferred charges and other assets | Commodity contracts |  |
Derivatives Fair Value [Line Items] |  |
Gross financial instruments, assets |  | 709
Not Designated As Hedges: | Deferred credits and other liabilities | Commodity contracts |  |
Derivatives Fair Value [Line Items] |  |
Gross financial instruments, liabilities |  | $ (1,129)

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- Definition Fair value, after the effects of contract netting under the master netting arrangements and prior to the offset of cash collateral, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. + References No definition available. + Details
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