Retirement Benefits - Schedule of Significant Assumptions Used in Determining Net Periodic Benefit Cost (Income) and Benefit Obligations (Details)	12 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2024
U.S. Plans \| Pension Benefits
Net periodic benefit cost assumptions
Discount rate	5.35%	5.10%	6.10%
Expected return on plan assets	7.00%	7.00%	7.00%
Compensation increase rate	3.50%	3.60%	3.60%
U.S. Plans \| Other Postretirement Benefits
Net periodic benefit cost assumptions
Discount rate	5.05%	4.91%	5.95%
Expected return on plan assets	0.00%	0.00%	0.00%
Compensation increase rate	0.00%	0.00%	0.00%
Non-U.S. Plans \| Pension Benefits
Net periodic benefit cost assumptions
Discount rate	4.07%	3.87%	4.65%
Expected return on plan assets	5.31%	5.24%	5.13%
Compensation increase rate	2.85%	3.22%	3.24%
Non-U.S. Plans \| Other Postretirement Benefits
Net periodic benefit cost assumptions
Discount rate	4.45%	4.45%	5.75%
Expected return on plan assets	0.00%	0.00%	0.00%
Compensation increase rate	0.00%	0.00%	0.00%

Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (j)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-5

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

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- Definition

Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (j)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-5

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-8

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (k)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

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- Definition

Weighted average rate of compensation increase used to determine net periodic benefit cost of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (j)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-5

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

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- References

No definition available.

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