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, 2017	Sep. 30, 2016	Sep. 30, 2015
Change in fair value of plan assets [Roll Forward]
Fair value of plan assets, beginning	$ 5,019
Fair value of plan assets, ending	5,528	$ 5,019
U.S. Plans [Member]
Change in projected benefit obligation [Roll Forward]
Projected benefit obligation, beginning	4,696	4,263
Service cost	60	59	$ 69
Interest cost	134	148	182
Actuarial (gain) loss	(144)	565
Benefits paid	(201)	(191)
Settlements	(125)	(151)
Acquisitions (Divestitures), net	(55)	0
Foreign currency translation and other	4	3
Projected benefit obligation, ending	4,369	4,696	4,263
Change in fair value of plan assets [Roll Forward]
Fair value of plan assets, beginning	4,110	3,928
Actual return on plan assets	516	491
Employer contributions	20	31
Benefits paid	(201)	(191)
Settlements	(125)	(151)
Acquisitions (Divestitures), net	(30)	0
Foreign currency translation and other	2	2
Fair value of plan assets, ending	4,292	4,110	3,928
Net amount recognized in the balance sheet	(77)	(586)
Noncurrent asset	154	0
Current liability	(11)	(11)
Noncurrent liability	(220)	(565)
Net liability held-for-sale	0	(10)
Pretax accumulated other comprehensive loss	(923)	(1,527)
Non-U.S. Plans [Member]
Change in projected benefit obligation [Roll Forward]
Projected benefit obligation, beginning	1,320	1,248
Service cost	19	26	37
Interest cost	30	39	46
Actuarial (gain) loss	(83)	275
Benefits paid	(29)	(31)
Settlements	(25)	(82)
Acquisitions (Divestitures), net	163	(6)
Foreign currency translation and other	94	(149)
Projected benefit obligation, ending	1,489	1,320	1,248
Change in fair value of plan assets [Roll Forward]
Fair value of plan assets, beginning	909	935
Actual return on plan assets	61	155
Employer contributions	25	35
Benefits paid	(29)	(31)
Settlements	(25)	(82)
Acquisitions (Divestitures), net	232	0
Foreign currency translation and other	63	(103)
Fair value of plan assets, ending	1,236	909	$ 935
Net amount recognized in the balance sheet	(253)	(411)
Noncurrent asset	43	1
Current liability	(11)	(7)
Noncurrent liability	(285)	(279)
Net liability held-for-sale		(126)
Pretax accumulated other comprehensive loss	(238)	$ (389)
Discontinued Operations, Held-for-sale [Member] | Non-U.S. Plans [Member]
Change in fair value of plan assets [Roll Forward]
Net liability held-for-sale	$ 0