Pension & Postretirement Expenses (Schedule Of Net Periodic Pension And Net Postretirement Plan Expenses) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension And Postretirement Plan Expenses [Line Items]
Total			$ 50	$ (1)
Other Pension, Postretirement and Supplemental Plans [Member]
Pension And Postretirement Plan Expenses [Line Items]
Service cost	$ 21	$ 18	65	54
Interest cost	40	49	120	149
Expected return on plan assets	(84)	(88)	(252)	(264)
Net amortization	38	17	113	50
Total	$ 15	$ (4)	$ 46	$ (11)