Retirement Plans (Schedule Of Retirement Plans Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Net periodic pension expense	$ 67	$ 2	$ 49
Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost (benefits earned during the period)	30	24	24
Interest cost	30	38	39
Expected return on plan assets	(72)	(68)	(67)
Net amortization and other	17	6	14
Net periodic pension expense	5	0	10
Defined contribution plans	56	56	52
Total retirement plans expense	61	56	62
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost (benefits earned during the period)	57	47	52
Interest cost	125	155	141
Expected return on plan assets	(268)	(281)	(283)
Net amortization and other	148	81	129
Net periodic pension expense	62	2	39
Defined contribution plans	112	125	132
Total retirement plans expense	$ 174	$ 127	$ 171