Unaudited Condensed Consolidated Statements Of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
CASH FLOWS FROM OPERATIONS:
Net income	$ 89,725,000	$ 62,552,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	248,846,000	212,292,000
Amortization of deferred financing costs and debt discounts	2,735,000	2,889,000
Deferred income taxes and investment tax credit adjustments - net	8,072,000	32,735,000
Allowance for equity funds used during construction	(3,585,000)	(7,089,000)
Gain (Loss) on Disposition of Intangible Assets	1,422,000	0
Change in certain assets and liabilities:
Accounts receivable	(69,259,000)	32,200,000
Inventories	16,845,000	(30,264,000)
Accounts payable	(52,219,000)	(28,669,000)
Accrued and other current liabilities	(11,292,000)	2,137,000
Accrued taxes payable/receivable	26,944,000	(20,103,000)
Accrued interest	50,174,000	11,325,000
Pension and other postretirement benefit assets and liabilities	1,840,000	1,390,000
Current and non-current regulatory assets and liabilities	(119,289,000)	100,822,000
Prepayments and other current assets	(819,000)	9,728,000
Increase (Decrease) in Other Noncurrent Liabilities	5,173,000	(9,226,000)
Other - net	(5,707,000)	(6,176,000)
Net cash provided by operating activities	191,244,000	347,087,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(727,152,000)	(453,671,000)
Project development costs	(3,164,000)	(4,589,000)
Payments to Acquire Businesses, Net of Cash Acquired	(48,368,000)	0
Cost of removal payments	(26,080,000)	(36,749,000)
Net cash used in investing activities	(804,764,000)	(534,759,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings under revolving credit facilities	570,000,000	75,000,000
Repayments under revolving credit facilities	(675,000,000)	0
Borrowings under revolving credit facilities	300,000,000	0
Other Short-Term Borrowings	92,000,000	0
Short-term borrowings from affiliate	1,050,000,000	0
Repayments of Short-term Debt	(392,000,000)	0
Retirement of long-term borrowings	(405,000,000)	0
Distributions to shareholders	110,146,000	66,941,000
Proceeds from Contributions from Parent	150,000,000	0
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(2,459,000)	0
Noncontrolling Interest, Increase from Sale of Parent Equity Interest	(46,935,000)	0
Payments for financing fees	(14,173,000)	(85,000)
Proceeds received from termination of interest rate swaps	23,114,000	0
Payments of Financing Costs	(22,000)	(313,000)
Net cash provided by financing activities	633,249,000	7,661,000
Net change in cash, cash equivalents and restricted cash	19,729,000	(180,011,000)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	48,313,000	21,542,000
Cash paid during the period for:
Interest (net of amount capitalized)	78,842,000	82,541,000
Non-cash investing activities:
Capital Expenditures Incurred but Not yet Paid	162,662,000	106,674,000
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	72,066,000	983,000
Change in Right-of-Use Asset Lease Liability	(69,089,000)	(1,408,000)
Proceeds from Insurance Settlement, Investing Activities	0	4,900,000
Payments to Acquire Intangible Assets	$ 0	$ (44,650,000)