CONSOLIDATED STATEMENTS OF INCOME (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Operating Revenues
Total Operating Revenues	$ 333,043	$ 342,336	$ 670,396	$ 689,404
Operating Expenses
Electric Production Fuel	16,292	12,324	30,613	30,018
Electric Purchased Power	15,497	9,249	46,367	31,771
Electric Operating and Maintenance Expenses	46,804	44,652	95,685	92,630
Cost of Products Sold (excluding depreciation)	105,966	116,795	210,353	231,518
Nonelectric Selling, General, and Administrative Expenses	17,352	18,154	38,644	37,067
Depreciation and Amortization	29,447	26,632	58,822	52,528
Electric Property Taxes	4,227	3,619	8,455	7,986
Total Operating Expenses	235,585	231,425	488,939	483,518
Operating Income	97,458	110,911	181,457	205,886
Other Income and (Expense)
Interest Expense	(11,720)	(10,202)	(23,273)	(20,052)
Nonservice Components of Postretirement Benefits	854	2,388	2,136	4,830
Other Income (Expense), net	4,788	4,490	9,244	9,069
Income Before Income Taxes	91,380	107,587	169,564	199,733
Income Tax Expense	13,652	20,592	23,737	38,400
Net Income	$ 77,728	$ 86,995	$ 145,827	$ 161,333
Weighted-Average Common Shares Outstanding:
Basic (in shares)	41,874	41,784	41,850	41,754
Diluted (in shares)	42,118	42,068	42,090	42,051
Earnings Per Share:
Basic (in dollars per share)	$ 1.86	$ 2.08	$ 3.48	$ 3.86
Diluted (in dollars per share)	$ 1.85	$ 2.07	$ 3.46	$ 3.84
Electric
Operating Revenues
Total Operating Revenues	$ 128,731	$ 112,828	$ 278,451	$ 254,317
Product Sales
Operating Revenues
Total Operating Revenues	$ 204,312	$ 229,508	$ 391,945	$ 435,087