Retirement Plan And Other Post-Retirement Benefits (Schedule Of Cumulative Amounts Recognized In AOCI (Loss) And Regulatory Assets And Liabilities) (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2021 USD ($)	[1]
Non-Qualified Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial Gain (Loss)	$ (33,241)
Prior Service (Cost) Credit	0
Net Amount Recognized	(33,241)
Decrease (Increase) in Actuarial Loss, excluding amortization	(5,029)	[2]
Change due to Amortization of Actuarial Loss	5,852
Prior Service (Cost) Credit	0
Net Change	823
Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial Gain (Loss)	(105,532)
Prior Service (Cost) Credit	(3,009)
Net Amount Recognized	(108,541)
Decrease (Increase) in Actuarial Loss, excluding amortization	72,985	[2]
Change due to Amortization of Actuarial Loss	36,814
Prior Service (Cost) Credit	631
Net Change	110,430
Other Post-Retirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial Gain (Loss)	26,112
Prior Service (Cost) Credit	1,972
Net Amount Recognized	28,084
Decrease (Increase) in Actuarial Loss, excluding amortization	53,307	[2]
Change due to Amortization of Actuarial Loss	849
Prior Service (Cost) Credit	(429)
Net Change	$ 53,727

[1] Amounts presented are shown before recognizing deferred taxes.

[2] Amounts presented include the impact of actuarial gains/losses related to return on assets, as well as the Actuarial (Gain) Loss amounts presented in the Change in Benefit Obligation.