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, 2019			34,668,000	17,348,000
Beginning balance, value at Dec. 31, 2019		$ 777,589		$ 17,348	$ 222,917	$ 397,021	$ 0	$ 140,303
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	$ 92,418	85,523				63,130		22,393
Capital contributions from parent		30,000			30,000
Cash dividends paid to parent by MGE		0
Distributions to parent from noncontrolling interest		(21,500)						(21,500)
Ending balance, shares at Dec. 31, 2020			36,163,000	17,348,000
Ending balance, value at Dec. 31, 2020		871,612		$ 17,348	252,917	460,151	0	141,196
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	105,761	100,782				78,391		22,391
Capital contributions from parent		0
Cash dividends paid to parent by MGE		(5,000)				(5,000)
Distributions to parent from noncontrolling interest		(15,000)						(15,000)
Ending balance, shares at Dec. 31, 2021			36,163,000	17,348,000
Ending 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