Retirement Plans Projected Benefit Payments from Plans (Details) $ in Millions	12 Months Ended
Sep. 30, 2021 USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total employer and employee contributions to defined benefit plans	$ 65
Voluntary contributions made by the company to defined benefit plans	0
Estimated future employer contributions to defined benefit plans in next fiscal year	42
Projected prescription drug subsidy receipts per year over the next ten years	1
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
2022	329
2023	298
2024	285
2025	280
2026	284
2027-2031	1,387
Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total employer and employee contributions to defined benefit plans	3
Estimated future employer contributions to defined benefit plans in next fiscal year	3
2022	11
2023	11
2024	11
2025	10
2026	10
2027-2031	$ 38

Defined benefit plan aggregate contributions.

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Voluntary contributions made by the company to defined benefit plans.

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

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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.

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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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Amount of contribution expected to be received by defined benefit plan from employer in next fiscal year following current fiscal year.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 18
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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.

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Amount of (increase) decrease in net periodic benefit cost from government subsidy for prescription drug benefits.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 60
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