Fair Value of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2025

Fair Value Disclosures [Abstract]

Estimated Fair Market Value of Financial Instruments

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

	September 30, 2025				December 31, 2024
(In thousands)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Long-term debt(a)	$	769,450	$	722,222	$	773,400	$	698,765

(a)Includes long-term debt due within one year. Excludes debt issuance costs and unamortized discount of $4.0 million and $4.4 million as of September 30, 2025, and December 31, 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 September 30, 2025
(In thousands)	Total		Level 1		Level 2		Level 3
Assets:
Derivatives, net(a)	$	1,961	$	1,105	$	—	$	856
Liabilities:
Derivatives, net(a)	$	1,984	$	1,840	$	—	$	144
Deferred compensation		6,859		—		6,859		—
Total Liabilities	$	8,843	$	1,840	$	6,859	$	144

	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 September 30, 2025, and December 31, 2024, collateral of $0.3 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.

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
(In thousands)	2025		2024		2025		2024
Beginning balance	$	197	$	(1,432)	$	(447)	$	(2,604)
Realized and unrealized gains (losses):
Included in regulatory assets		—		300		—		1,472
Included in regulatory liability		515		—		1,158		—
Included in earnings		(456)		(1,572)		(1,722)		(5,174)
Settlements		456		1,572		1,723		5,174
Balance as of September 30,	$	712	$	(1,132)	$	712	$	(1,132)

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 gains (losses) included in income for Level 3 assets and liabilities measured at fair value on a recurring basis(b).

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
(In thousands)	2025		2024		2025		2024
Purchased power expense	$	(456)	$	(1,572)	$	(1,722)	$	(5,174)

(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.