Fair Value Measurements (Tables)

3 Months Ended

Dec. 31, 2024

Fair Value Disclosures [Abstract]

Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table presents, on a gross basis, our financial assets and liabilities, including both current and noncurrent portions, that are measured at fair value on a recurring basis within the fair value hierarchy:

	Asset (Liability)
	Level 1		Level 2		Level 3		Total
December 31, 2024:
Derivative instruments:
Assets:
Commodity contracts	$	130	$	33	$	—	$	163
Foreign currency contracts	$	—	$	33	$	—	$	33
Interest rate contracts	$	—	$	5	$	—	$	5
Liabilities:
Commodity contracts	$	(98)	$	(14)	$	—	$	(112)
Foreign currency contracts	$	—	$	(1)	$	—	$	(1)
Interest rate contracts	$	—	$	(9)	$	—	$	(9)
Non-qualified supplemental postretirement grantor trust investments (a)	$	44	$	—	$	—	$	44
September 30, 2024:
Derivative instruments:
Assets:
Commodity contracts	$	106	$	27	$	—	$	133
Foreign currency contracts	$	—	$	6	$	—	$	6
Interest rate contracts	$	—	$	1	$	—	$	1
Liabilities:
Commodity contracts	$	(120)	$	(32)	$	—	$	(152)
Foreign currency contracts	$	—	$	(9)	$	—	$	(9)
Interest rate contracts	$	—	$	(22)	$	—	$	(22)
Non-qualified supplemental postretirement grantor trust investments (a)	$	43	$	—	$	—	$	43
December 31, 2023:
Derivative instruments:
Assets:
Commodity contracts	$	112	$	50	$	—	$	162
Foreign currency contracts	$	—	$	12	$	—	$	12
Interest rate contracts	$	—	$	15	$	—	$	15
Liabilities:
Commodity contracts	$	(227)	$	(104)	$	—	$	(331)
Foreign currency contracts	$	—	$	(6)	$	—	$	(6)
Interest rate contracts	$	—	$	(16)	$	—	$	(16)
Non-qualified supplemental postretirement grantor trust investments (a)	$	42	$	—	$	—	$	42

(a)Consists primarily of mutual fund investments held in grantor trusts associated with non-qualified supplemental retirement plans.

Schedule of Carrying Amount and Estimated Fair Value of Long-term Debt

The carrying amounts and estimated fair values of our long-term debt (including current maturities but excluding unamortized debt issuance costs) were as follows:

	December 31, 2024		September 30, 2024		December 31, 2023
Carrying amount	$	6,907	$	6,733	$	6,866
Estimated fair value	$	6,523	$	6,663	$	6,644