Schedule II - Valuation and Qualifying Accounts (Details) - USD ($)		12 Months Ended
		Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period		$ 9,029,742	$ 8,098,076	$ 8,372,840
Charged to costs and expenses	[1]	5,850,001	4,850,000	3,264,309
Charged to other accounts		51,600	54,000	20,400
Net accounts written off	[2]	(4,269,143)	(3,972,334)	(3,559,473)
Balance at end of period		10,662,201	9,029,742	8,098,076
Deferred Bad Debt Expense [Member]
Regulatory Asset [Line Items]
Regulatory assets		1,900,000	$ 400,000	$ 1,500,000
Collection of Bad Debt Expense [Member]
Regulatory Asset [Line Items]
Regulatory assets		$ (4,900,000)

[1] For both the years ended December 31, 2025 and 2024, MGE recovered $4.9 million of bad debt expense as a regulatory asset. For the years ended December 31, 2025, 2024, and 2023, MGE deferred $1.9 million, $0.4 million, and $1.5 million, respectively, of bad debt expense as a regulatory asset. See Footnote 8 of the Notes to Consolidated Financial Statements in this Report for further information.

[2] Net of recovery of amounts previously written off.