Fair Value Measurements (Tables)

12 Months Ended

Sep. 30, 2020

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, 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
September 30, 2019
Derivative instruments:
Assets:
Commodity contracts	$	32	$	10	$	—	$	42
Foreign currency contracts	$	—	$	59	$	—	$	59
Liabilities:
Commodity contracts	$	(62)	$	(113)	$	—	$	(175)
Foreign currency contracts	$	—	$	(4)	$	—	$	(4)
Interest rate contracts	$	—	$	(12)	$	—	$	(12)
Non-qualified supplemental postretirement grantor trust investments (a)	$	40	$	—	$	—	$	40

(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:

	2020		2019
Carrying amount	$	6,081	$	5,857
Estimated fair value	$	6,504	$	6,189