Pension & Postretirement Plans (Schedule Of Net Periodic Pension And Net Postretirement Plan Expenses) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 21	$ 21	$ 63	$ 65
Interest cost	32	40	96	120
Expected return on plan assets	(84)	(84)	(252)	(252)
Net amortization	35	38	105	113
Total	$ 4	$ 15	$ 12	$ 46