CONSOLIDATED STATEMENTS OF INCOME (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Operating Revenues
Total Operating Revenues	$ 342,336	$ 337,716	$ 689,404	$ 676,797
Operating Expenses
Electric Production Fuel	12,324	14,833	30,018	26,326
Electric Purchased Power	9,249	5,212	31,771	47,037
Electric Operating and Maintenance Expenses	44,652	45,522	92,630	91,070
Cost of Products Sold (excluding depreciation)	116,795	120,658	231,518	233,027
Nonelectric Selling, General, and Administrative Expenses	18,154	16,870	37,067	35,568
Depreciation and Amortization	26,632	24,232	52,528	48,089
Electric Property Taxes	3,619	4,336	7,986	8,957
Total Operating Expenses	231,425	231,663	483,518	490,074
Operating Income	110,911	106,053	205,886	186,723
Other Income and (Expense)
Interest Expense	(10,202)	(9,696)	(20,052)	(19,111)
Nonservice Components of Postretirement Benefits	2,388	2,421	4,830	4,833
Other Income (Expense), net	4,490	3,253	9,069	5,370
Income Before Income Taxes	107,587	102,031	199,733	177,815
Income Tax Expense	20,592	20,062	38,400	33,365
Net Income	$ 86,995	$ 81,969	$ 161,333	$ 144,450
Weighted-Average Common Shares Outstanding:
Basic (in shares)	41,784	41,678	41,754	41,655
Diluted (in shares)	42,068	42,053	42,051	42,035
Earnings Per Share:
Basic (in dollars per share)	$ 2.08	$ 1.97	$ 3.86	$ 3.47
Diluted (in dollars per share)	$ 2.07	$ 1.95	$ 3.84	$ 3.44
Electric
Operating Revenues
Total Operating Revenues	$ 112,828	$ 113,763	$ 254,317	$ 265,671
Product Sales
Operating Revenues
Total Operating Revenues	$ 229,508	$ 223,953	$ 435,087	$ 411,126