Summary Of Significant Accounting Policies (Components Of Other Current Assets) (Details) - USD ($) $ in Thousands		Sep. 30, 2021	Sep. 30, 2020
Summary Of Significant Accounting Policies [Line Items]
Prepayments		$ 14,164	$ 12,851
Prepaid Property and Other Taxes		14,788	14,269
Regulatory Assets	[1]	29,206	16,609
Other Current Assets		59,660	47,557
State [Member]
Summary Of Significant Accounting Policies [Line Items]
Income Taxes Receivable		$ 1,502	$ 3,828

[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.