Retirement Plans (Schedule Of Retirement Plans Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Net periodic pension expense	$ 2	$ 49	$ 127
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost (benefits earned during the period)	24	24	19
Interest cost	38	39	30
Expected return on plan assets	(68)	(67)	(56)
Net amortization and other	6	14	22
Net periodic pension expense	0	10	15
Defined contribution plans	56	52	47
Total retirement plans expense	56	62	62
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost (benefits earned during the period)	47	52	60
Interest cost	155	141	134
Expected return on plan assets	(281)	(283)	(290)
Net amortization and other	81	129	211
Net periodic pension expense	2	39	115
Defined contribution plans	125	132	96
Total retirement plans expense	$ 127	$ 171	$ 211