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, 2018	Sep. 30, 2017	Sep. 30, 2016
Change in fair value of plan assets [Roll Forward]
Fair value of plan assets, beginning	$ 5,528
Fair value of plan assets, ending	5,476	$ 5,528
Noncurrent asset	591	197
U.S. Plans
Change in projected benefit obligation [Roll Forward]
Projected benefit obligation, beginning	4,369	4,696
Service cost	52	60	$ 59
Interest cost	141	134	148
Actuarial (gain) loss	(262)	(144)
Benefits paid	(205)	(201)
Settlements	(152)	(125)
Acquisitions (Divestitures), net	13	(55)
Foreign currency translation and other	1	4
Projected benefit obligation, ending	3,957	4,369	4,696
Change in fair value of plan assets [Roll Forward]
Fair value of plan assets, beginning	4,292	4,110
Actual return on plan assets	265	516
Employer contributions	20	20
Benefits paid	(205)	(201)
Settlements	(152)	(125)
Acquisitions (Divestitures), net	12	(30)
Foreign currency translation and other	1	2
Fair value of plan assets, ending	4,233	4,292	4,110
Net amount recognized in the balance sheet	276	(77)
Noncurrent asset	465	154
Current liability	(10)	(11)
Noncurrent liability	(179)	(220)
Pretax accumulated other comprehensive loss	(548)	(923)
Non-U.S. Plans
Change in projected benefit obligation [Roll Forward]
Projected benefit obligation, beginning	1,489	1,320
Service cost	24	19	26
Interest cost	39	30	39
Actuarial (gain) loss	(51)	(83)
Benefits paid	(36)	(29)
Settlements	(49)	(25)
Acquisitions (Divestitures), net	54	163
Foreign currency translation and other	(28)	94
Projected benefit obligation, ending	1,442	1,489	1,320
Change in fair value of plan assets [Roll Forward]
Fair value of plan assets, beginning	1,236	909
Actual return on plan assets	69	61
Employer contributions	41	25
Benefits paid	(36)	(29)
Settlements	(49)	(25)
Acquisitions (Divestitures), net	10	232
Foreign currency translation and other	(28)	63
Fair value of plan assets, ending	1,243	1,236	$ 909
Net amount recognized in the balance sheet	(199)	(253)
Noncurrent asset	126	43
Current liability	(13)	(11)
Noncurrent liability	(312)	(285)
Pretax accumulated other comprehensive loss	$ (164)	$ (238)

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

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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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Fair value of assets that have been segregated and restricted to provide pension or postretirement benefits. Assets include, but are not limited to, stocks, bonds, other investments, earnings from investments, and contributions by the employer and employees.

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Amount of cost recognized for passage of time related to defined benefit plan.

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Amount of payment to participant under defined benefit plan which decreases plan assets. 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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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 (increase) decrease to benefit obligation of defined benefit plan from irrevocable action relieving primary responsibility for benefit obligation and eliminating risk for obligation and assets used to effect settlement. Includes, but is not limited to, lump-sum cash payment to participant in exchange for right to receive specified benefits, purchase of nonparticipating annuity contract and change from remeasurement.

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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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