Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2025

Fair Value Disclosures [Abstract]

Estimated Fair Market Value of Financial Instruments

The estimated fair market value of financial instruments are as follows:

	December 31, 2025				December 31, 2024
(In thousands)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Long-term debt(a)	$	818,115	$	768,889	$	773,400	$	698,765

(a)Includes long-term debt due within one year. Excludes debt issuance costs and unamortized discount of $4.3 million and $4.4 million as of December 31, 2025 and 2024, respectively.

Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table presents the balances of assets and liabilities measured at fair value on a recurring basis for both MGE and MGE Energy.

	Fair Value as of December 31, 2025
(In thousands)	Total		Level 1		Level 2		Level 3
Assets:
Derivatives, net(a)	$	1,151	$	568	$	—	$	583
Liabilities:
Derivatives, net(a)	$	2,565	$	1,331	$	—	$	1,234
Deferred compensation		7,172		—		7,172		—
Total Liabilities	$	9,737	$	1,331	$	7,172	$	1,234

	Fair Value as of December 31, 2024
(In thousands)	Total		Level 1		Level 2		Level 3
Assets:
Derivatives, net(a)	$	1,321	$	987	$	—	$	334
Liabilities:
Derivatives, net(a)	$	1,261	$	480	$	—	$	781
Deferred compensation		6,468		—		6,468		—
Total Liabilities	$	7,729	$	480	$	6,468	$	781

(a)As of December 31, 2025, and 2024, collateral of $1.8 million and less than $0.1 million, respectively, was posted against and netted with derivative liability positions. The fair value of the derivatives disclosed in this table has not been adjusted for the collateral posted.

Changes in Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table summarizes the changes in Level 3 commodity derivative assets and liabilities measured at fair value on a recurring basis.

(In thousands)	2025			2024			2023
Realized and unrealized gains (losses):
Included in regulatory assets	$	(205	)	$	—		$	(1,738	)
Included in regulatory liability		—			2,159			—
Included in earnings		(1,602	)		(6,209	)		(9,211	)
Settlements		1,603			6,207			9,211

Gains and Losses Included in Income for Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table presents total realized and unrealized losses included in income for Level 3 assets and liabilities measured at fair value on a recurring basis(b).

(In thousands)
Year Ended December 31,	2025			2024			2023
Purchased power expense	$	(1,602	)	$	(6,209	)	$	(9,211	)

(b)MGE's exchange-traded derivative contracts, over-the-counter party transactions, purchased power agreement, and FTRs are subject to regulatory deferral. These derivatives are therefore marked to fair value and are offset in the financial statements with a corresponding regulatory asset or liability.