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Commitments and Contingencies (Details-1) (USD $) In Millions, unless otherwise specified | 3 Months Ended
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Mar. 31, 2015 ppb MW
Columbia Environmental Project, SCR [Member] | MGE [Member] |
Columbia Commitments |
Share of projected project cost, minimum | 30 mgee_PublicUtilitiesColumbiaCleanAirActLitigationShareOfProjectedProjectCostMinimum / mgee_ConstructionProjectAxis = mgee_ColumbiaEnvironmentalProjectScrMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember
Share of projected project cost, maximum | 40 mgee_PublicUtilitiesColumbiaCleanAirActLitigationShareOfProjectedProjectCostMaximum / mgee_ConstructionProjectAxis = mgee_ColumbiaEnvironmentalProjectScrMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember
EPA [Member] | Legal Entity Type of Counterparty [Domain] |
Effluent Limitations Guidelines and Standards for Steam Electric Power Generating Source Category [Abstract] |
Proposed air pollution control and ash handling systems capacity at coal burning power plants, minimum (in MW) | 50 mgee_PublicUtilitiesEffluentLimitationsGuidelinesProposedAirPollutionControlAndAshHandlingSystemsCapacityMinimum / dei_LegalEntityAxis = us-gaap_LegalEntityTypeOfCounterpartyDomain / us-gaap_RegulatoryAgencyAxis = mgee_UnitedStatesEnvironmentalProtectionAgencyMember
EPA's Greenhouse Gas Reduction Guidelines |
National average reduction of greenhouse gas emissions by the year 2030, percentage | 30.00%mgee_PublicUtilitiesGreenhouseGasEmissionsReductionGuidelinesNationalAverageReductionRequirementBy2030Percentage / dei_LegalEntityAxis = us-gaap_LegalEntityTypeOfCounterpartyDomain / us-gaap_RegulatoryAgencyAxis = mgee_UnitedStatesEnvironmentalProtectionAgencyMember
Wisconsin state average reduction goal of greenhouse gas emissions by the year 2030, percentage | 34.00%mgee_PublicUtilitiesGreenhouseGasEmissionsReductionGuidelinesWisconsinStateAverageReductionGoalBy2030Percentage / dei_LegalEntityAxis = us-gaap_LegalEntityTypeOfCounterpartyDomain / us-gaap_RegulatoryAgencyAxis = mgee_UnitedStatesEnvironmentalProtectionAgencyMember
Compliance plan preparation term related to the greenhouse gas emissions reduction guidelines once the final rule is approved in 2015 | 2 years
Ozone NAAQS |
Proposed lowered regulated level of Ozone NAAQS, minimum (in parts per billion) | 65 mgee_PublicUtilitiesNationalAmbientAirQualityStandardsProposedLoweredRegulatedOzoneNaaqsLevelMinimum / dei_LegalEntityAxis = us-gaap_LegalEntityTypeOfCounterpartyDomain / us-gaap_RegulatoryAgencyAxis = mgee_UnitedStatesEnvironmentalProtectionAgencyMember
Proposed lowered regulated level of Ozone NAAQS, maximum (in parts per billion) | 70 mgee_PublicUtilitiesNationalAmbientAirQualityStandardsProposedLoweredRegulatedOzoneNaaqsLevelMaximum / dei_LegalEntityAxis = us-gaap_LegalEntityTypeOfCounterpartyDomain / us-gaap_RegulatoryAgencyAxis = mgee_UnitedStatesEnvironmentalProtectionAgencyMember
Current regulated level of Ozone NAAQS (in parts per billion) | 75 mgee_PublicUtilitiesNationalAmbientAirQualityStandardsCurrentRegulatedOzoneNaaqsLevel / dei_LegalEntityAxis = us-gaap_LegalEntityTypeOfCounterpartyDomain / us-gaap_RegulatoryAgencyAxis = mgee_UnitedStatesEnvironmentalProtectionAgencyMember
Proposed lowered regulated level of Ozone NAAQS, potential additional minimum (in parts per billion) | 60 mgee_PublicUtilitiesNationalAmbientAirQualityStandardsProposedLoweredRegulatedOzoneNaaqsLevelAdditionalMinimum / dei_LegalEntityAxis = us-gaap_LegalEntityTypeOfCounterpartyDomain / us-gaap_RegulatoryAgencyAxis = mgee_UnitedStatesEnvironmentalProtectionAgencyMember
EPA's Coal Combustion Residuals Rule |
Federal Register publication waiting period to become effective, term | 6 months

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- Definition The waiting period after publication in the Federal Register for the Coal Combustion Residuals from Electric Utilities rule to become effective. + References No definition available. + Details
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- Definition The Company's maximum share of the projected project cost under the Columbia Clean Air Act. + References No definition available. + Details
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- Definition The Company's minimum share of the projected project cost under the Columbia Clean Air Act. + References No definition available. + Details
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- Definition The proposed air pollution control and ash handling systems capacity minimum as required by the Effluent Limitations Guidelines. + References No definition available. + Details
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- Definition The term allowed for preparation of the compliance plan once the final rule is approved in 2015 for the national average of greenhouse gas emissions required by the year 2030 for electric generating units. + References No definition available. + Details
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- Definition The percentage reduction of the national average of greenhouse gas emissions required by the year 2030 for electric generating units. + References No definition available. + Details
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- Definition The percentage reduction goal of the Wisconsin state average of greenhouse gas emissions by the year 2030 for electric generating units. + References No definition available. + Details
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- Definition The current regulated level of Ozone NAAQS by the National Ambient Air Quality Standards. + References No definition available. + Details
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- Definition The proposed lowered regulated additional minimum level of Ozone NAAQS by the National Ambient Air Quality Standards. + References No definition available. + Details
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- Definition The proposed lowered regulated maximum level of Ozone NAAQS by the National Ambient Air Quality Standards. + References No definition available. + Details
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- Definition The proposed lowered regulated minimum level of Ozone NAAQS by the National Ambient Air Quality Standards. + References No definition available. + Details
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