Fair Value Measurements (Tables)

3 Months Ended

Dec. 31, 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:

	Asset (Liability)
	Level 1		Level 2		Level 3		Total
December 31, 2021:
Derivative instruments:
Assets:
Commodity contracts	$	411	$	711	$	—	$	1,122
Foreign currency contracts	$	—	$	29	$	—	$	29
Interest rate contracts	$	—	$	5	$	—	$	5
Liabilities:
Commodity contracts	$	(160)	$	(18)	$	—	$	(178)
Foreign currency contracts	$	—	$	(7)	$	—	$	(7)
Interest rate contracts	$	—	$	(17)	$	—	$	(17)
Non-qualified supplemental postretirement grantor trust investments (a)	$	52	$	—	$	—	$	52
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
December 31, 2020:
Derivative instruments:
Assets:
Commodity contracts	$	60	$	111	$	—	$	171
Foreign currency contracts	$	—	$	14	$	—	$	14
Liabilities:
Commodity contracts	$	(58)	$	(14)	$	—	$	(72)
Foreign currency contracts	$	—	$	(25)	$	—	$	(25)
Interest rate contracts	$	—	$	(50)	$	—	$	(50)
Non-qualified supplemental postretirement grantor trust investments (a)	$	46	$	—	$	—	$	46

(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, 2021		September 30, 2021		December 31, 2020
Carrying amount	$	6,580	$	6,491	$	6,078
Estimated fair value	$	7,048	$	6,996	$	6,581