Restructuring - Restructuring Activities and Related Reserves (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Restructuring Cost and Reserve [Line Items]
Reserve balance	$ 0
Charges	13	$ 4	$ 3
Costs charged against assets	(6)
Cash paid	(6)
Reserve balance	1	0
Severance and Employee Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Reserve balance	0
Charges	5
Cash paid	(5)
Reserve balance	0	0
Accelerated Depreciation on Assets [Member]
Restructuring Cost and Reserve [Line Items]
Reserve balance	0
Charges	6
Costs charged against assets	(6)
Reserve balance	0	0
Other [Member]
Restructuring Cost and Reserve [Line Items]
Reserve balance	0
Charges	2
Cash paid	(1)
Reserve balance	$ 1	$ 0

Costs charged against assets liabilities.

No definition available.

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- Definition

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 420
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482017/420-10-50-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
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-Publisher FASB
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+ Details

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- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 420
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-Section S99
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-Publisher FASB
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482047/420-10-45-3

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 420
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+ Details

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 420
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4.d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479823/420-10-S99-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 420
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479823/420-10-S99-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 2
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479823/420-10-S99-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 420
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-URI https://asc.fasb.org/1943274/2147482017/420-10-50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 420
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-Name Accounting Standards Codification
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-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482017/420-10-50-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482017/420-10-50-1

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- Definition

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

+ Details

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- Details

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