Retirement Plan And Other Post-Retirement Benefits (Schedule Of Significant Unobservable Input Changes In Plan Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance, Beginning of Year	$ 2,931	$ 2,976
Unrealized Gains/(Losses)	(2,495)	(42)
Sales	0	(3)
Balance, End of Year	436	2,931
Retirement Plan [Member] | Excluding 401(h) Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance, Beginning of Year	(223)	(218)
Unrealized Gains/(Losses)	188	(5)
Sales	0	0
Balance, End of Year	(35)	(223)
Retirement Plan [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance, Beginning of Year	3,154	3,194
Unrealized Gains/(Losses)	(2,683)	(37)
Sales	0	(3)
Balance, End of Year	471	3,154
Other Post-Retirement Benefit Plans [Member] | 401(h) Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance, Beginning of Year	223	218
Unrealized Gains/(Losses)	(188)	5
Sales	0	0
Balance, End of Year	$ 35	$ 223