Retirement Plans (Reconciliations Of Actuarial Present Value Of Projected Benefit Obligations And Fair Value Of Plan Assets For Defined Benefit Pension Plans) (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Change in fair value of plan assets [Roll Forward]
Fair value of plan assets, beginning	$ 5,476
Fair value of plan assets, ending	5,492	$ 5,476
Noncurrent asset	164	591
U.S. Plans
Change in projected benefit obligation [Roll Forward]
Projected benefit obligation, beginning	3,957	4,369
Service cost	47	52	$ 60
Interest cost	155	141	134
Actuarial (gain) loss	608	(262)
Benefits paid	(206)	(205)
Settlements	(152)	(152)
Acquisitions (Divestitures), net	0	13
Foreign currency translation and other	1	1
Projected benefit obligation, ending	4,410	3,957	4,369
Change in fair value of plan assets [Roll Forward]
Fair value of plan assets, beginning	4,233	4,292
Actual return on plan assets	316	265
Employer contributions	16	20
Benefits paid	(206)	(205)
Settlements	(152)	(152)
Acquisitions (Divestitures), net	0	12
Foreign currency translation and other	1	1
Fair value of plan assets, ending	4,208	4,233	4,292
Net amount recognized in the balance sheet	(202)	276
Noncurrent asset	67	465
Current liability	(11)	(10)
Noncurrent liability	(258)	(179)
Pretax accumulated other comprehensive loss	(1,040)	(548)
Non-U.S. Plans
Change in projected benefit obligation [Roll Forward]
Projected benefit obligation, beginning	1,442	1,489
Service cost	24	24	19
Interest cost	38	39	30
Actuarial (gain) loss	216	(51)
Benefits paid	(36)	(36)
Settlements	(41)	(49)
Acquisitions (Divestitures), net	2	54
Foreign currency translation and other	(61)	(28)
Projected benefit obligation, ending	1,584	1,442	1,489
Change in fair value of plan assets [Roll Forward]
Fair value of plan assets, beginning	1,243	1,236
Actual return on plan assets	135	69
Employer contributions	44	41
Benefits paid	(36)	(36)
Settlements	(41)	(49)
Acquisitions (Divestitures), net	0	10
Foreign currency translation and other	(61)	(28)
Fair value of plan assets, ending	1,284	1,243	$ 1,236
Net amount recognized in the balance sheet	(300)	(199)
Noncurrent asset	97	126
Current liability	(14)	(13)
Noncurrent liability	(383)	(312)
Pretax accumulated other comprehensive loss	$ (307)	$ (164)

Defined Benefit Plan, Acquisitions and Divestitures, Net

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Fair Value of Plan Assets, Acquisitions and Divestitures, Net

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Fair Value of Plan Assets, Foreign Currency Translation And Other

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Amount of liability, recognized in statement of financial position, for defined benefit pension plan, classified as current. Excludes other postretirement benefit plan.

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Amount of liability, recognized in statement of financial position, for defined benefit pension plan, classified as noncurrent. Excludes other postretirement benefit plan.

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

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Amount of increase (decrease) in plan assets of defined benefit plan from actual return (loss) determined by change in fair value of plan assets adjusted for contributions, benefit payments, and other expenses.

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Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan.

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

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Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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Amount of payment to participant of defined benefit plan which decreases benefit obligation. For pension plan, payment includes, but is not limited to, pension benefits and death benefits. For other postretirement plan, payment includes, but is not limited to, prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of contribution received by defined benefit plan from employer which increases plan assets.

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Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.

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Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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Amount of payment, which decreases plan assets of defined benefit plan, for irrevocable action relieving primary responsibility for benefit obligation and eliminating risk for obligation and assets used to effect settlement. Transaction constituting settlement includes, but is not limited to, making lump-sum cash payment to participant in exchange for their rights to receive specified benefits and purchasing nonparticipating annuity contract.

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