Pension & Postretirement Expenses (Schedule Of Net Periodic Pension And Net Postretirement Plan Expenses) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 21	$ 22	$ 42	$ 44
Interest cost	32	40	64	80
Expected return on plan assets	(84)	(84)	(168)	(168)
Net amortization	35	38	70	75
Total	$ 4	$ 16	$ 8	$ 31