v3.25.3

Pension and Other Postretirement Plans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Defined Benefit Plan Deferred Pension And Other Postretirement Benefit Plan Costs Recovered [Abstract]
Deferred (recognized) pension and OPEB costs		$ (500)	$ (700)	$ (3,100)
Pension Benefits [Member]
Components of net periodic benefit cost:
Service cost	$ 653	769	1,959	2,308
Interest cost	4,285	4,280	12,854	12,839
Expected return on assets	(7,254)	(7,149)	(21,761)	(21,448)
Amortization of:
Actuarial (gain) loss	75	215	225	644
Net periodic benefit (credit) cost	(2,241)	(1,885)	(6,723)	(5,657)
Postretirement Benefits [Member]
Components of net periodic benefit cost:
Service cost	186	214	557	642
Interest cost	757	778	2,271	2,354
Expected return on assets	(678)	(675)	(2,036)	(2,059)
Settlement cost	0	288	0	288
Amortization of:
Transition obligation	1	1	2	2
Prior service credit	0	(234)	0	(242)
Actuarial (gain) loss	(161)	774	(482)	568
Net periodic benefit (credit) cost	$ 105	$ 1,146	$ 312	$ 1,553

Amount of net periodic benefit cost for pension and postretirement deferred (recognized prior year deferral) for the difference between estimated costs included in the rate settlement and actual costs incurred

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Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan.

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Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan.

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Amount of transition asset (obligation) recognized in net periodic benefit (cost) credit of defined benefit plan.

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Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan.

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Amount of cost recognized for passage of time related to defined benefit plan.

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Amount of net periodic benefit cost (credit) for defined benefit plan.

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Amount of gain (loss) recognized in net periodic benefit (cost) credit from irrevocable action relieving primary responsibility for benefit obligation and eliminating risk related to obligation and assets used to effect settlement.

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Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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MGE ENERGY INC 10-Q