Schedule I - Condensed Parent Company Finanical Statements (Details-Notes 1) - USD ($) $ in Thousands		Dec. 31, 2025	Dec. 31, 2024
Line of Credit Facility [Line Items]
Line of credit, borrowings outstanding		$ 0
MGE Energy unsecured committed revolving line of credit totaling $50 million [Member] | MGE Energy [Member]
Line of Credit Facility [Line Items]
Line of credit		50,000
Line of credit, borrowings outstanding		0	$ 0
Line of Credit [Member]
Line of Credit Facility [Line Items]
Available capacity under line of credit	[1],[2]	86,917	179,383
Line of credit	[2],[3]	$ 180,000	$ 180,000

[1] Available capacity under the Company’s line of credit is calculated as total committed revolving credit capacity less commercial paper outstanding as of December 31, 2025. The $2.0 million unsecured promissory note, issued to the seller in connection with a land acquisition, is included in short‑term debt outstanding but is not a borrowing under the Company’s revolving credit facilities. The promissory note was fully repaid, including interest, in January 2026.

[2] MGE Energy short-term borrowings include MGE Energy and MGE lines of credit and MGE commercial paper.

[3] As of December 31, 2025, MGE Energy and MGE had no borrowings outstanding under these credit facilities and were in compliance with the covenant requirements of the credit agreements.