Retirement Benefits - Schedule of Expected Benefit Payments (Details) $ in Millions	Sep. 30, 2026 USD ($)
Pension Benefits
Estimated future benefit payments
2027	$ 223
2028	216
2029	212
2030	210
2031	215
2032-2036	1,003
Other Postretirement Benefits
Estimated future benefit payments
2027	6
2028	5
2029	5
2030	4
2031	4
2032-2036	$ 14

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- Definition

Amount of benefit for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following current fiscal year.

+ References

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

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Amount of benefit for defined benefit plan expected to be paid in next fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in fifth fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in fourth fiscal year following current fiscal year.

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Amount of benefit for defined benefit plan expected to be paid in third fiscal year following current fiscal year.

+ References

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Amount of benefit for defined benefit plan expected to be paid in second fiscal year following current fiscal year.

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