Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Operating Revenues:
Electric revenues	$ 532,231	$ 498,357	$ 490,419
Gas revenue	211,423	178,587	200,012
Total Operating Revenues	743,654	676,944	690,431
Operating Expenses:
Fuel for electric generation	70,847	53,994	57,627
Purchased power	20,004	32,852	41,224
Cost of gas sold	107,026	82,693	106,647
Other operations and maintenance	236,880	228,576	215,891
Depreciation and amortization	114,324	108,581	100,352
Other general taxes	23,920	23,986	22,305
Total Operating Expenses	573,001	530,682	544,046
Operating Income	170,653	146,262	146,385
Other income, net	19,800	17,833	29,546
Interest (expense) income, net	(33,799)	(32,930)	(30,429)
Income before income taxes	156,654	131,165	145,502
Income tax provision	(20,765)	(10,596)	(27,803)
Net Income Including Noncontrolling Interest	135,889	120,569	117,699
Net Income	$ 135,889	$ 120,569	$ 117,699
Earnings Per Share of Common Stock, Basic	$ 3.72	$ 3.33	$ 3.25
Earnings Per Share of Common Stock, Diluted	3.72	3.33	3.25
Dividends per share of common stock	$ 1.85	$ 1.76	$ 1.67
Weighted Average Shares Outstanding, Basic	36,534	36,210	36,163
Weighted Average Shares Outstanding, Diluted	36,571	36,239	36,186
MGE [Member]
Operating Revenues:
Electric revenues	$ 532,231	$ 498,357	$ 490,419
Gas revenue	211,423	178,587	200,012
Total Operating Revenues	743,654	676,944	690,431
Operating Expenses:
Fuel for electric generation	70,847	53,994	57,627
Purchased power	20,004	32,852	41,224
Cost of gas sold	107,026	82,693	106,647
Other operations and maintenance	235,835	227,671	214,897
Depreciation and amortization	114,324	108,581	100,352
Other general taxes	23,920	23,986	22,301
Total Operating Expenses	571,956	529,777	543,048
Operating Income	171,698	147,167	147,383
Other income, net	6,549	5,885	21,365
Interest (expense) income, net	(34,102)	(33,369)	(30,651)
Income before income taxes	144,145	119,683	138,097
Income tax provision	(17,348)	(7,384)	(25,727)
Net Income Including Noncontrolling Interest	126,797	112,299	112,370
Less Net Income Attributable to Noncontrolling Interest, net of tax	(22,652)	(22,855)	(21,868)
Net Income	$ 104,145	$ 89,444	$ 90,502