XML 119 R98.htm IDEA: XBRL DOCUMENT
v3.25.4

Fair Value of Financial Instruments (Details-3) | 12 Months Ended
--- | ---
Dec. 31, 2025
Deferred compensation plan [Abstract] |
Investment interest calculation, investment maturity period (26 weeks) | 182 days
Investment interest calculation, monthly compounding rate | 1.00%
Investment interest calculation, minimum annual rate compounded monthly | 7.00%

X
- Definition Investment maturity period used in deferred compensation interest calculation. + References No definition available. + Details
Name: | mgee_DeferredCompensationArrangementWithIndividualInvestmentInterestCalculationInvestmentMaturityPeriod
Namespace Prefix: | mgee_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Minimum annual rate compounded monthly used in deferred compensation interest calculation. + References No definition available. + Details
Name: | mgee_DeferredCompensationArrangementWithIndividualInvestmentInterestCalculationMinimumAnnualRateCompoundedMonthly
Namespace Prefix: | mgee_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage increase compounded monthly used in deferred compensation interest calculation. + References No definition available. + Details
Name: | mgee_DeferredCompensationArrangementWithIndividualInvestmentInterestCalculationMonthlyCompoundingRate
Namespace Prefix: | mgee_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DeferredCompensationArrangementsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration