Name:	mgee_EnergyEfficiencyAndRenewablesAbstract
Namespace Prefix:	mgee_
Data Type:	xbrli:stringItemType
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The ACE proposal directs states to submit plans to the EPA for approval that implement standards of performance (called Best System of Emissions Reductions, or BSER) for individual EGUs over a certain threshold.

No definition available.

Name:	mgee_EpaGreenhouseGasReductionGuidlinesStandardOfPerformanceForEgus
Namespace Prefix:	mgee_
Data Type:	num:powerItemType
Balance Type:	na
Period Type:	instant

- References

No definition available.

Name:	mgee_EpasCrossStateAirPollutionRuleAbstract
Namespace Prefix:	mgee_
Data Type:	xbrli:stringItemType
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Period Type:	duration

Percentage the sector is projected to reduce GHG emissions below 2005 levels under Clean Power Plan Rule.

No definition available.

Name:	mgee_EpasGreenhouseGasReductionGuidlinesReductioninGhgEmissionsPercentage
Namespace Prefix:	mgee_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- References

No definition available.

Name:	mgee_NationalAmbientAirQualityStandardsAbstract
Namespace Prefix:	mgee_
Data Type:	xbrli:stringItemType
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Period Type:	duration

The minimum electricity generated from renewable resources set by regulatory agency

No definition available.

Name:	mgee_PublicUtilitiesMinimumElectricityGeneratedFromRenewableResourcesBy2015
Namespace Prefix:	mgee_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The number of pollutants monitored by the National Ambient Air Quality Standards.

No definition available.

Name:	mgee_PublicUtilitiesNationalAmbientAirQualityStandardsNumberOfPollutantsMonitored
Namespace Prefix:	mgee_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The number of states identified by the EPA's Cross State Air Pollution Rule that are subject to the proposed amendment which incorporate 2008 Ozone NAAQS levels.

No definition available.