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Pension Benefit Obligations - Target Allocation and Plan Assets Allocations (Details)	Sep. 30, 2023	Sep. 30, 2022
United States
Percentage of Plan Assets:
Target allocations (as a percent)	100.00%
Percentage of Plan Assets (as a percent)	100.00%	100.00%
United States | Equities
Percentage of Plan Assets:
Target allocations (as a percent)	32.00%
Percentage of Plan Assets (as a percent)	33.00%	36.00%
United States | Debt
Percentage of Plan Assets:
Target allocations (as a percent)	58.00%
Percentage of Plan Assets (as a percent)	56.00%	48.00%
United States | Cash
Percentage of Plan Assets:
Target allocations (as a percent)	2.00%
Percentage of Plan Assets (as a percent)	2.00%	5.00%
United States | Property And Other
Percentage of Plan Assets:
Target allocations (as a percent)	8.00%
Percentage of Plan Assets (as a percent)	9.00%	11.00%
International
Percentage of Plan Assets:
Target allocations (as a percent)	100.00%
Percentage of Plan Assets (as a percent)	100.00%	100.00%
International | Equities
Percentage of Plan Assets:
Target allocations (as a percent)	27.00%
Percentage of Plan Assets (as a percent)	24.00%	20.00%
International | Debt
Percentage of Plan Assets:
Target allocations (as a percent)	61.00%
Percentage of Plan Assets (as a percent)	62.00%	47.00%
International | Cash
Percentage of Plan Assets:
Percentage of Plan Assets (as a percent)	4.00%	15.00%
International | Property And Other
Percentage of Plan Assets:
Target allocations (as a percent)	12.00%
Percentage of Plan Assets (as a percent)	10.00%	18.00%

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- Definition

Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480482/715-20-55-17

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

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- Definition

Percentage of actual investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

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