Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating Revenues:
Electric revenues	$ 116,568,000	$ 120,821,000	$ 303,556,000	$ 315,367,000
Gas revenue	18,643,000	17,377,000	98,568,000	112,547,000
Total Operating Revenues	135,211,000	138,198,000	402,124,000	427,914,000
Operating Expenses:
Fuel for electric generation	12,945,000	15,901,000	31,343,000	40,221,000
Purchased power	10,708,000	9,126,000	32,050,000	31,013,000
Cost of gas sold	3,812,000	3,092,000	40,950,000	55,220,000
Other operations and maintenance	45,819,000	48,070,000	136,412,000	143,979,000
Depreciation and amortization	18,592,000	18,193,000	55,193,000	53,423,000
Other general taxes	5,010,000	5,078,000	14,892,000	15,026,000
Total Operating Expenses	96,886,000	99,460,000	310,840,000	338,882,000
Operating Income	38,325,000	38,738,000	91,284,000	89,032,000
Other income, net	6,534,000	5,204,000	19,131,000	15,074,000
Interest expense, net	(5,765,000)	(5,831,000)	(17,740,000)	(17,227,000)
Income before income taxes	39,094,000	38,111,000	92,675,000	86,879,000
Income tax provision	(7,300,000)	(7,454,000)	(16,053,000)	(16,667,000)
Net Income Including Noncontrolling Interest	31,794,000	30,657,000	76,622,000	70,212,000
Net Income	$ 31,794,000	$ 30,657,000	$ 76,622,000	$ 70,212,000
Earnings Per Share of Common Stock (basic and diluted)	$ 0.88	$ 0.88	$ 2.16	$ 2.03
Dividends per share of common stock	$ 0.370	$ 0.353	$ 1.075	$ 1.028
Weighted Average Shares Outstanding (basic and diluted)	36,163	34,668	35,427	34,668
MGE [Member]
Operating Revenues:
Electric revenues	$ 116,568,000	$ 120,821,000	$ 303,556,000	$ 315,367,000
Gas revenue	18,643,000	17,377,000	98,568,000	112,547,000
Total Operating Revenues	135,211,000	138,198,000	402,124,000	427,914,000
Operating Expenses:
Fuel for electric generation	12,945,000	15,901,000	31,343,000	40,221,000
Purchased power	10,708,000	9,126,000	32,050,000	31,013,000
Cost of gas sold	3,812,000	3,092,000	40,950,000	55,220,000
Other operations and maintenance	45,591,000	47,947,000	135,634,000	143,282,000
Depreciation and amortization	18,592,000	18,193,000	55,193,000	53,423,000
Other general taxes	5,010,000	5,078,000	14,892,000	15,026,000
Total Operating Expenses	96,658,000	99,337,000	310,062,000	338,185,000
Operating Income	38,553,000	38,861,000	92,062,000	89,729,000
Other income, net	4,093,000	2,672,000	11,005,000	7,837,000
Interest expense, net	(5,802,000)	(6,095,000)	(17,848,000)	(18,223,000)
Income before income taxes	36,844,000	35,438,000	85,219,000	79,343,000
Income tax provision	(6,611,000)	(6,687,000)	(14,028,000)	(14,579,000)
Net Income Including Noncontrolling Interest	30,233,000	28,751,000	71,191,000	64,764,000
Less Net Income Attributable to Noncontrolling Interest, net of tax	(5,493,000)	(5,614,000)	(16,754,000)	(16,725,000)
Net Income	$ 24,740,000	$ 23,137,000	$ 54,437,000	$ 48,039,000