Fair Value Measurements Fair Value Measurements Using Significant Unobservable Inputs (Details) - USD ($) $ in Millions	Jun. 30, 2025	Sep. 30, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contract derivatives	$ 6	$ 7
Commodity contract derivatives	5	5
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity contract derivatives	0	0
Commodity contract derivatives	$ 0	$ 0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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