Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating Activities:
Net Margin including Non-controlling interest	$ 11,960	$ 12,843	$ 11,770
Adjustments to reconcile net margin to net cash provided by operating activities:
Depreciation and amortization	70,258	69,573	69,167
Other non-cash charges	17,581	17,173	16,192
Change in current assets	(5,796)	(924)	(119,343)
Change in deferred energy	70,104	114,538	(78,831)
Change in current liabilities	38,546	(164,849)	80,459
Change in regulatory assets and liabilities	66,137	(106,202)	(19,453)
Change in other assets and other liabilities	(11,341)	41,580	(19,567)
Net Cash Provided by (Used for) Operating Activities	257,449	(16,268)	(59,606)
Investing Activities:
Purchases of held to maturity securities			(80,012)
Proceeds from sale of held to maturity securities			80,600
Purchases of available for sale securities	(15,000)
Proceeds from sale of available for sale securities	15,000
Increase in other investments	(17,335)	(5,925)	(3,491)
Electric plant additions	(55,668)	(52,943)	(31,089)
Net Cash Used for Investing Activities	(73,003)	(58,868)	(33,992)
Financing Activities:
Debt issuance costs		(752)
Payments of long-term debt	(49,041)	(49,041)	(49,041)
Draws on revolving credit facility	246,500	528,000	152,500
Repayments on revolving credit facility	(372,500)	(387,000)	(102,500)
Net Cash (Used for) Provided by Financing Activities	(175,041)	91,207	959
Net Change in Cash and Cash Equivalents	9,405	16,071	(92,639)
Cash and Cash Equivalents - Beginning of Period	31,284	15,213	107,852
Cash and Cash Equivalents - End of Period	$ 40,689	$ 31,284	$ 15,213