Fair Value Measurements (Tables)

12 Months Ended

Sep. 30, 2021

Fair Value Disclosures [Abstract]

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 as described in Note 2:

	Asset (Liability)
	Level 1		Level 2		Level 3		Total
September 30, 2021:
Derivative instruments:
Assets:
Commodity contracts	$	641	$	1,008	$	—	$	1,649
Foreign currency contracts	$	—	$	38	$	—	$	38
Liabilities:
Commodity contracts	$	(264)	$	(16)	$	—	$	(280)
Foreign currency contracts	$	—	$	(8)	$	—	$	(8)
Interest rate contracts	$	—	$	(29)	$	—	$	(29)
Non-qualified supplemental postretirement grantor trust investments (a)	$	53	$	—	$	—	$	53
September 30, 2020
Derivative instruments:
Assets:
Commodity contracts	$	68	$	39	$	—	$	107
Foreign currency contracts	$	—	$	32	$	—	$	32
Liabilities:
Commodity contracts	$	(54)	$	(64)	$	—	$	(118)
Foreign currency contracts	$	—	$	(14)	$	—	$	(14)
Interest rate contracts	$	—	$	(55)	$	—	$	(55)
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 (see Note 8).

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:

	2021		2020
Carrying amount	$	6,491	$	6,081
Estimated fair value	$	6,996	$	6,504