Amount of total entity’s unfunded plans.

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Defined contribution and multiemployer plans

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Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level.

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Amount, before tax, of accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

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Amount of asset (liability), recognized in statement of financial position, for defined benefit pension and other postretirement plans.

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- Definition

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

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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 cost (credit) included in accumulated other comprehensive (income) loss expected to be recognized in net periodic benefit cost (credit) for fiscal year following most recent annual statement of financial position.

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

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

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

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

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

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

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Amount of funded (unfunded) status of defined benefit plan, measured as difference between fair value of plan assets and benefit obligation. Includes, but is not limited to, overfunded (underfunded) status.

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Amount of net periodic benefit cost (credit) for defined benefit plan.

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Amount of accumulated benefit obligation for defined benefit plan with accumulated benefit obligation in excess of plan assets.

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Amount of plan asset for defined benefit plan with accumulated benefit obligation in excess of plan assets.

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Amount of projected benefit obligation for defined benefit pension plan with accumulated benefit obligation in excess of plan assets.

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Amount of cash outflow for pension benefit. Includes, but is not limited to, employer contribution to fund plan asset and payment to retiree. Excludes other postretirement benefit.

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Retirement Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Gains (Losses) deferred in accumulated other comprehensive income will be amortized into earnings in 2020		$ (162)
Losses deferred in accumulated other comprehensive income		(1,347)
Total accumulated benefit obligation		5,682	$ 5,154
Accumulated benefit obligations in excess of plan assets for retirement plans, projected benefit obligation		1,113	585
Accumulated benefit obligations in excess of plan assets for retirement plans, accumulated benefit obligation		991	508
Accumulated benefit obligations in excess of plan assets for retirement plans, fair value of plan assets		456	87
Pension contribution		60	61	$ 45
Net periodic pension expense		2	49	$ 127
Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension contribution	$ 60
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Funded status of plan		(202)	$ 276
Over (Under) funded plans		(202)
Unfunded plans		(211)
Future benefit payments, 2020		208
Future benefit payments, 2021		215
Future benefit payments, 2022		222
Future benefit payments, 2023		228
Future benefit payments, 2024		234
Total future benefit payments, 2025 - 2029		$ 1,233
Discount rate		3.22%	4.26%	3.76%
Net periodic pension expense		$ 2	$ 39	$ 115
Defined contribution plans		125	132	96
U.S. Plans \| Discontinued Operations, Disposed of by Sale [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic pension expense				3
Defined contribution plans				$ 6
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Funded status of plan		(300)	$ (199)
Over (Under) funded plans		(300)
Unfunded plans		(311)
Future benefit payments, 2020		74
Future benefit payments, 2021		72
Future benefit payments, 2022		78
Future benefit payments, 2023		80
Future benefit payments, 2024		84
Total future benefit payments, 2025 - 2029		$ 462
Discount rate		1.90%	2.70%	2.60%
Net periodic pension expense		$ 0	$ 10	$ 15
Defined contribution plans		$ 56	$ 52	$ 47