Madison Gas and Electric Company Consolidated Statements of Equity - USD ($) $ in Thousands	Total	MGE [Member]	Common Stock [Member]	Common Stock [Member] MGE [Member]	Additional Paid-in Capital [Member] MGE [Member]	Retained Earnings [Member] MGE [Member]	Accumulated Other Comprehensive (Loss)/ Income [Member] MGE [Member]	Noncontrolling Interest [Member] MGE [Member]
Beginning balance, shares at Dec. 31, 2021			36,163,000	17,348,000
Beginning balance, value at Dec. 31, 2021		$ 952,394		$ 17,348	$ 252,917	$ 533,542	$ 0	$ 148,587
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	$ 110,952	105,492				83,916		21,576
Capital contributions from parent		0
Cash dividends paid to parent by MGE		(33,500)				(33,500)
Distributions to parent from noncontrolling interest		(22,000)						(22,000)
Ending balance, shares at Dec. 31, 2022			36,163,000	17,348,000
Ending balance, value at Dec. 31, 2022		1,002,386		$ 17,348	252,917	583,958	0	148,163
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	117,699	112,370				90,502		21,868
Capital contributions from parent		0
Cash dividends paid to parent by MGE		(41,000)				(41,000)
Distributions to parent from noncontrolling interest		(20,500)						(20,500)
Ending balance, shares at Dec. 31, 2023			36,163,000	17,348,000
Ending balance, value at Dec. 31, 2023		1,053,256		$ 17,348	252,917	633,460	0	149,531
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	$ 120,569	112,299				89,444		22,855
Capital contributions from parent		30,750			30,750
Cash dividends paid to parent by MGE		(34,500)				(34,500)
Distributions to parent from noncontrolling interest		(22,000)						(22,000)
Ending balance, shares at Dec. 31, 2024			36,490,000	17,348,000
Ending balance, value at Dec. 31, 2024		$ 1,139,805		$ 17,348	$ 283,667	$ 688,404	$ 0	$ 150,386