Pension & Postretirement Expenses (Schedule Of Net Periodic Pension And Net Postretirement Plan Expenses) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Pension And Postretirement Plan Expenses [Line Items]
Total	$ 17	$ 0
Other Pension, Postretirement and Supplemental Plans [Member]
Pension And Postretirement Plan Expenses [Line Items]
Service cost	22	18
Interest cost	40	50
Expected return on plan assets	(84)	(88)
Net amortization	37	17
Total	$ 15	$ (3)