Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Revenues:
Electric revenues	$ 490,419	$ 465,847	$ 420,964
Gas revenue	200,012	248,672	185,620
Total Operating Revenues	690,431	714,519	606,584
Operating Expenses:
Fuel for electric generation	57,627	61,329	54,633
Purchased power	41,224	46,821	39,395
Cost of gas sold	106,647	152,570	99,690
Other operations and maintenance	215,891	209,875	199,316
Depreciation and amortization	100,352	85,549	76,983
Other general taxes	22,305	20,632	19,273
Total Operating Expenses	544,046	576,776	489,290
Operating Income	146,385	137,743	117,294
Other income, net	29,546	26,080	16,694
Interest (expense) income, net	(30,429)	(26,647)	(24,112)
Income before income taxes	145,502	137,176	109,876
Income tax provision	(27,803)	(26,224)	(4,115)
Net Income Including Noncontrolling Interest	117,699	110,952	105,761
Net Income	$ 117,699	$ 110,952	$ 105,761
Earnings Per Share of Common Stock, Basic	$ 3.25	$ 3.07	$ 2.92
Earnings Per Share of Common Stock, Diluted	3.25	3.07	2.92
Dividends per share of common stock	$ 1.67	$ 1.59	$ 1.52
Weighted Average Shares Outstanding, Basic	36,163	36,163	36,163
Weighted Average Shares Outstanding, Diluted	36,186	36,174	36,167
MGE [Member]
Operating Revenues:
Electric revenues	$ 490,419	$ 465,847	$ 420,964
Gas revenue	200,012	248,672	185,620
Total Operating Revenues	690,431	714,519	606,584
Operating Expenses:
Fuel for electric generation	57,627	61,329	54,633
Purchased power	41,224	46,821	39,395
Cost of gas sold	106,647	152,570	99,690
Other operations and maintenance	214,897	209,007	198,552
Depreciation and amortization	100,352	85,549	76,983
Other general taxes	22,301	20,627	19,269
Total Operating Expenses	543,048	575,903	488,522
Operating Income	147,383	138,616	118,062
Other income, net	21,365	17,626	9,121
Interest (expense) income, net	(30,651)	(26,687)	(24,153)
Income before income taxes	138,097	129,555	103,030
Income tax provision	(25,727)	(24,063)	(2,248)
Net Income Including Noncontrolling Interest	112,370	105,492	100,782
Less Net Income Attributable to Noncontrolling Interest, net of tax	(21,868)	(21,576)	(22,391)
Net Income	$ 90,502	$ 83,916	$ 78,391