Regulatory Matters (Schedule Of Regulatory Assets And Liabilities) (Details) - USD ($) $ in Thousands		Sep. 30, 2022	Sep. 30, 2021
Regulatory Assets And Liabilities [Line Items]
Total Regulatory Assets	[1]	$ 203,590	$ 221,932
Less: Amounts Included in Other Current Assets	[1]	(21,358)	(29,206)
Total Long-Term Regulatory Assets		67,101	60,145
Total Regulatory Liabilities		842,560	861,249
Less: Amounts Included in Current and Accrued Liabilities		(31,712)	(60,881)
Total Long-Term Regulatory Liabilities		188,803	200,643
Cost Of Removal Regulatory Liability [Member]
Regulatory Assets And Liabilities [Line Items]
Total Regulatory Liabilities		259,947	245,636
Taxes Refundable To Customers [Member]
Regulatory Assets And Liabilities [Line Items]
Total Regulatory Liabilities		362,098	354,089
Post-Retirement Benefit Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Total Regulatory Liabilities	[2]	167,305	213,112
Less: Amounts Included in Current and Accrued Liabilities		(5,800)	(30,000)
Total Long-Term Regulatory Liabilities		161,505	183,112
Pension Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Total Regulatory Liabilities	[3]	8,242	0
Amounts Payable To Customers [Member]
Regulatory Assets And Liabilities [Line Items]
Total Regulatory Liabilities		419	21
Other [Member]
Regulatory Assets And Liabilities [Line Items]
Total Regulatory Liabilities	[4]	44,549	48,391
Total Long-Term Regulatory Liabilities		19,056	17,531
Non-Current Regulatory Liabilities [Member]
Regulatory Assets And Liabilities [Line Items]
Total Long-Term Regulatory Liabilities		810,848	800,368
Other Accruals and Current Liabilities [Member]
Regulatory Assets And Liabilities [Line Items]
Less: Amounts Included in Current and Accrued Liabilities		(25,493)	(30,860)
Pension Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Total Regulatory Assets	[1],[5]	11,677	21,655
Post-Retirement Benefit Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Total Regulatory Assets	[1],[5]	6,814	10,075
Recoverable Future Taxes [Member]
Regulatory Assets And Liabilities [Line Items]
Total Regulatory Assets	[1]	106,247	121,992
Environmental Site Remediation Costs [Member]
Regulatory Assets And Liabilities [Line Items]
Total Regulatory Assets	[1],[5]	3,646	7,256
Asset Retirement Obligations [Member]
Regulatory Assets And Liabilities [Line Items]
Total Regulatory Assets	[1],[5]	18,517	16,799
Unamortized Debt Expense [Member]
Regulatory Assets And Liabilities [Line Items]
Total Regulatory Assets	[1]	8,884	10,589
Other [Member]
Regulatory Assets And Liabilities [Line Items]
Total Regulatory Assets	[1],[6]	47,805	33,566
Total Long-Term Regulatory Assets		26,447	4,360
Long-Term Regulatory Assets [Member]
Regulatory Assets And Liabilities [Line Items]
Total Long-Term Regulatory Assets	[1]	182,232	192,726
Other Current Assets [Member]
Regulatory Assets And Liabilities [Line Items]
Less: Amounts Included in Other Current Assets		$ (21,358)	$ (29,206)

[1] The Company recovers the cost of its regulatory assets but generally does not earn a return on them. There are a few exceptions to this rule. For example, the Company does earn a return on Unrecovered Purchased Gas Costs and, in the New York jurisdiction of its Utility segment, earns a return, within certain parameters, on the excess of cumulative funding to the pension plan over the cumulative amount collected in rates.

[2] $5,800 and $30,000 are included in Other Accruals and Current Liabilities on the Consolidated Balance Sheets at September 30, 2022 and 2021, respectively, since such amounts are expected to be passed back to ratepayers in the next 12 months. $161,505 and $183,112 are included in Other Regulatory Liabilities on the Consolidated Balance Sheets at September 30, 2022 and 2021, respectively.

[3] Included in Other Regulatory Liabilities on the Consolidated Balance Sheets.

[4] $25,493 and $30,860 are included in Other Accruals and Current Liabilities on the Consolidated Balance Sheets at September 30, 2022 and 2021, respectively, since such amounts are expected to be passed back to ratepayers in the next 12 months. $19,056 and $17,531 are included in Other Regulatory Liabilities on the Consolidated Balance Sheets at September 30, 2022 and 2021, respectively.

[5] Included in Other Regulatory Assets on the Consolidated Balance Sheets.

[6] $21,358 and $29,206 are included in Other Current Assets on the Consolidated Balance Sheets at September 30, 2022 and 2021, respectively, since such amounts are expected to be recovered from ratepayers in the next 12 months. $26,447 and $4,360 are included in Other Regulatory Assets on the Consolidated Balance Sheets at September 30, 2022 and 2021, respectively.