Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Revenues:
Electric revenues	$ 420,964	$ 394,372	$ 408,980
Gas revenues	185,620	144,261	159,875
Total Operating Revenues	606,584	538,633	568,855
Operating Expenses:
Fuel for electric generation	54,633	41,684	51,954
Purchased power	39,395	42,883	41,474
Cost of gas sold	99,690	63,697	79,775
Other operations and maintenance	199,316	186,430	193,322
Depreciation and amortization	76,983	74,188	71,562
Other general taxes	19,273	19,754	19,858
Total Operating Expenses	489,290	428,636	457,945
Operating Income	117,294	109,997	110,910
Other income, net	16,694	25,365	18,811
Interest expense, net	(24,112)	(23,521)	(23,063)
Income before income taxes	109,876	111,841	106,658
Income tax provision	(4,115)	(19,423)	(19,784)
Net Income Including Noncontrolling Interest	105,761	92,418	86,874
Net Income	$ 105,761	$ 92,418	$ 86,874
Earnings Per Share of Common Stock Basic	$ 2.92	$ 2.60	$ 2.51
Earnings Per Share of Common Stock Diluted	2.92	2.60	2.51
Dividends per share of common stock	$ 1.52	$ 1.45	$ 1.38
Weighted Average Shares Outstanding Basic	36,163	35,612	34,668
Weighted Average Shares Outstanding Diluted	36,167	35,612	34,668
MGE [Member]
Operating Revenues:
Electric revenues	$ 420,964	$ 394,372	$ 408,980
Gas revenues	185,620	144,261	159,875
Total Operating Revenues	606,584	538,633	568,855
Operating Expenses:
Fuel for electric generation	54,633	41,684	51,954
Purchased power	39,395	42,883	41,474
Cost of gas sold	99,690	63,697	79,775
Other operations and maintenance	198,552	185,450	192,440
Depreciation and amortization	76,983	74,188	71,562
Other general taxes	19,269	19,750	19,858
Total Operating Expenses	488,522	427,652	457,063
Operating Income	118,062	110,981	111,792
Other income, net	9,121	15,019	10,703
Interest expense, net	(24,153)	(23,642)	(24,298)
Income before income taxes	103,030	102,358	98,197
Income tax provision	(2,248)	(16,835)	(17,418)
Net Income Including Noncontrolling Interest	100,782	85,523	80,779
Less Net Income Attributable to Noncontrolling Interest, net of tax	(22,391)	(22,393)	(22,349)
Net Income	$ 78,391	$ 63,130	$ 58,430