Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Operating Revenues:
Electric revenues	$ 120,821	$ 119,388	$ 315,367	$ 313,537
Gas revenue	17,377	18,407	112,547	106,152
Total Operating Revenues	138,198	137,795	427,914	419,689
Operating Expenses:
Fuel for electric generation	15,901	16,793	40,221	43,944
Purchased power	9,126	13,024	31,013	43,036
Cost of gas sold	3,092	4,921	55,220	54,109
Other operations and maintenance	48,070	44,130	143,979	131,976
Depreciation and amortization	18,193	14,259	53,423	41,754
Other general taxes	5,078	4,870	15,026	14,653
Total Operating Expenses	99,460	97,997	338,882	329,472
Operating Income	38,738	39,798	89,032	90,217
Other income, net	5,204	4,330	15,074	13,980
Interest expense, net	(5,831)	(5,025)	(17,227)	(14,547)
Income before income taxes	38,111	39,103	86,879	89,650
Income tax provision	(7,454)	(9,597)	(16,667)	(21,792)
Net Income Including Noncontrolling Interest	30,657	29,506	70,212	67,858
Net Income	$ 30,657	$ 29,506	$ 70,212	$ 67,858
Earnings Per Share of Common Stock (basic and diluted)	$ 0.88	$ 0.85	$ 2.03	$ 1.96
Dividends per share of common stock	$ 0.353	$ 0.338	$ 1.028	$ 0.983
Weighted Average Shares Outstanding (basic and diluted)	34,668	34,668	34,668	34,668
MGE [Member]
Operating Revenues:
Electric revenues	$ 120,821	$ 119,388	$ 315,367	$ 313,537
Gas revenue	17,377	18,407	112,547	106,152
Total Operating Revenues	138,198	137,795	427,914	419,689
Operating Expenses:
Fuel for electric generation	15,901	16,793	40,221	43,944
Purchased power	9,126	13,024	31,013	43,036
Cost of gas sold	3,092	4,921	55,220	54,109
Other operations and maintenance	47,947	43,987	143,282	131,175
Depreciation and amortization	18,193	14,259	53,423	41,754
Other general taxes	5,078	4,870	15,026	14,653
Total Operating Expenses	99,337	97,854	338,185	328,671
Operating Income	38,861	39,941	89,729	91,018
Other income, net	2,672	2,592	7,837	7,402
Interest expense, net	(6,095)	(5,500)	(18,223)	(15,727)
Income before income taxes	35,438	37,033	79,343	82,693
Income tax provision	(6,687)	(9,117)	(14,579)	(19,918)
Net Income Including Noncontrolling Interest	28,751	27,916	64,764	62,775
Less Net Income Attributable to Noncontrolling Interest, net of tax	(5,614)	(5,629)	(16,725)	(16,940)
Net Income	$ 23,137	$ 22,287	$ 48,039	$ 45,835