Investment in ATC and ATC Holdco (Details-1) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Schedule of Equity Method Investments [Line Items]
Equity earnings from investment			$ 8,427	$ 7,930
Dividends from investments			6,414	6,305
Capital contributions to investments			4,348	5,986
MGE Transco [Member] | ATC [Member]
Schedule of Equity Method Investments [Line Items]
Equity earnings from investment	$ 2,868	$ 2,662	8,338	7,844
Dividends from investments	2,176	2,057	6,414	6,305
Capital contributions to investments	$ 894	$ 1,075	$ 2,679	$ 3,033