Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating Revenues:
Electric revenues	$ 121,853	$ 116,568	$ 324,574	$ 303,556
Gas revenue	24,020	18,643	119,944	98,568
Total Operating Revenues	145,873	135,211	444,518	402,124
Operating Expenses:
Fuel for electric generation	18,486	12,945	42,570	31,343
Purchased power	8,646	10,708	28,914	32,050
Cost of gas sold	8,780	3,812	57,728	40,950
Other operations and maintenance	48,494	45,819	144,563	136,412
Depreciation and amortization	18,991	18,592	55,968	55,193
Other general taxes	4,878	5,010	14,730	14,892
Total Operating Expenses	108,275	96,886	344,473	310,840
Operating Income	37,598	38,325	100,045	91,284
Other (expense) income, net	6,164	6,534	14,353	19,131
Interest expense, net	(6,079)	(5,765)	(17,591)	(17,740)
Income before income taxes	37,683	39,094	96,807	92,675
Income tax benefit (provision)	(2,766)	(7,300)	(4,106)	(16,053)
Net Income Including Noncontrolling Interest	34,917	31,794	92,701	76,622
Net Income	$ 34,917	$ 31,794	$ 92,701	$ 76,622
Earnings per share of Common Stock - Basic	$ 0.97	$ 0.88	$ 2.56	$ 2.16
Earnings per share of Common Stock - Diluted	0.97	0.88	2.56	2.16
Dividends per share of common stock	$ 0.388	$ 0.370	$ 1.128	$ 1.075
Weighted Average Number Of Shares Outstanding Basic	36,163	36,163	36,163	35,427
Weighted Average Shares Outstanding - Diluted	36,170	36,163	36,176	35,427
MGE [Member]
Operating Revenues:
Electric revenues	$ 121,853	$ 116,568	$ 324,574	$ 303,556
Gas revenue	24,020	18,643	119,944	98,568
Total Operating Revenues	145,873	135,211	444,518	402,124
Operating Expenses:
Fuel for electric generation	18,486	12,945	42,570	31,343
Purchased power	8,646	10,708	28,914	32,050
Cost of gas sold	8,780	3,812	57,728	40,950
Other operations and maintenance	48,315	45,591	143,978	135,634
Depreciation and amortization	18,991	18,592	55,968	55,193
Other general taxes	4,878	5,010	14,730	14,892
Total Operating Expenses	108,096	96,658	343,888	310,062
Operating Income	37,777	38,553	100,630	92,062
Other (expense) income, net	3,306	4,093	6,375	11,005
Interest expense, net	(6,089)	(5,802)	(17,623)	(17,848)
Income before income taxes	34,994	36,844	89,382	85,219
Income tax benefit (provision)	(1,993)	(6,611)	(1,853)	(14,028)
Net Income Including Noncontrolling Interest	33,001	30,233	87,529	71,191
Less Net Income Attributable to Noncontrolling Interest, net of tax	(5,627)	(5,493)	(16,755)	(16,754)
Net Income	$ 27,374	$ 24,740	$ 70,774	$ 54,437