XML 28 R52.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Segment Information (Details) (USD $) In Thousands, unless otherwise specified | 3 Months Ended
--- | ---
Mar. 31, 2015 | Mar. 31, 2014
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | $ 170,134 us-gaap_RegulatedAndUnregulatedOperatingRevenue |  | $ 210,245 us-gaap_RegulatedAndUnregulatedOperatingRevenue |
Depreciation and amortization | (10,849)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization |  | (9,746)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization |
Other operating expenses | (127,434)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization |  | (156,528)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization |
Operating Income | 31,851 us-gaap_OperatingIncomeLoss |  | 43,971 us-gaap_OperatingIncomeLoss |
Other income (deductions), net | 2,105 us-gaap_NonoperatingIncomeExpense |  | 4,552 us-gaap_NonoperatingIncomeExpense |
Interest (expense) income, net | (5,091)us-gaap_InterestIncomeExpenseNet |  | (4,541)us-gaap_InterestIncomeExpenseNet |
Income before income taxes | 28,865 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic |  | 43,982 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic |
Income tax (provision) benefit | (10,587)us-gaap_IncomeTaxExpenseBenefit |  | (16,265)us-gaap_IncomeTaxExpenseBenefit |
Net Income (Loss) | 18,278 us-gaap_NetIncomeLoss |  | 27,717 us-gaap_NetIncomeLoss |
Electric [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 98,240 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | 98,852 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Gas [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 69,928 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | 110,713 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Non Regulated Energy [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 1,966 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | 680 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Transmission Investment [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
All Others [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |  | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |
Operating Segments [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 170,134 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember |  | 210,245 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember |
Operating Segments [Member] | Electric [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 98,355 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | 98,970 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Depreciation and amortization | (7,332)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | (6,337)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Other operating expenses | (79,800)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | (77,901)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Operating Income | 11,223 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | 14,732 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Other income (deductions), net | 90 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | 1,827 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Interest (expense) income, net | (2,819)us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | (2,205)us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Income before income taxes | 8,494 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | 14,354 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Income tax (provision) benefit | (2,383)us-gaap_IncomeTaxExpenseBenefit / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | (4,353)us-gaap_IncomeTaxExpenseBenefit / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Net Income (Loss) | 6,111 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | 10,001 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Operating Segments [Member] | Gas [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 72,653 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | 114,337 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Depreciation and amortization | (1,642)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | (1,563)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Other operating expenses | (60,068)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | (92,843)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Operating Income | 10,943 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | 19,931 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Other income (deductions), net | (1)us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | (35)us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Interest (expense) income, net | (804)us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | (804)us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Income before income taxes | 10,138 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | 19,092 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Income tax (provision) benefit | (4,081)us-gaap_IncomeTaxExpenseBenefit / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | (7,665)us-gaap_IncomeTaxExpenseBenefit / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Net Income (Loss) | 6,057 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | 11,427 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Operating Segments [Member] | Non Regulated Energy [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 11,813 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | 11,350 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Depreciation and amortization | (1,863)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | (1,834)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Other operating expenses | (50)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | (40)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Operating Income | 9,900 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | 9,476 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Other income (deductions), net | 0 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | 0 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Interest (expense) income, net | (1,518)us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | (1,572)us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Income before income taxes | 8,382 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | 7,904 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Income tax (provision) benefit | (3,364)us-gaap_IncomeTaxExpenseBenefit / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | (3,172)us-gaap_IncomeTaxExpenseBenefit / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Net Income (Loss) | 5,018 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | 4,732 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Operating Segments [Member] | Transmission Investment [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
Depreciation and amortization | 0 us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 0 us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
Other operating expenses | 0 mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 0 mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
Operating Income | 0 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 0 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
Other income (deductions), net | 1,881 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 2,481 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
Interest (expense) income, net | 0 us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 0 us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
Income before income taxes | 1,881 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 2,481 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
Income tax (provision) benefit | (756)us-gaap_IncomeTaxExpenseBenefit / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | (998)us-gaap_IncomeTaxExpenseBenefit / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
Net Income (Loss) | 1,125 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 1,483 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
Operating Segments [Member] | All Others [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |  | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |
Depreciation and amortization | (12)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |  | (12)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |
Other operating expenses | (203)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |  | (156)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |
Operating Income | (215)us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |  | (168)us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |
Other income (deductions), net | 135 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |  | 279 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |
Interest (expense) income, net | 50 us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |  | 40 us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |
Income before income taxes | (30)us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |  | 151 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |
Income tax (provision) benefit | (3)us-gaap_IncomeTaxExpenseBenefit / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |  | (77)us-gaap_IncomeTaxExpenseBenefit / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |
Net Income (Loss) | (33)us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |  | 74 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |
Consolidation Elimination Entries [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | (12,687)us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |  | (14,412)us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |
Depreciation and amortization | 0 us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |  | 0 us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |
Other operating expenses | 12,687 mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |  | 14,412 mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |
Operating Income | 0 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |  | 0 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |
Other income (deductions), net | 0 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |  | 0 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |
Interest (expense) income, net | 0 us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |  | 0 us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |
Income before income taxes | 0 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |  | 0 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |
Income tax (provision) benefit | 0 us-gaap_IncomeTaxExpenseBenefit / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |  | 0 us-gaap_IncomeTaxExpenseBenefit / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |
Net Income (Loss) | 0 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |  | 0 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember |
Consolidation Elimination Entries [Member] | Electric [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 115 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | 118 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Consolidation Elimination Entries [Member] | Gas [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 2,725 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | 3,624 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Consolidation Elimination Entries [Member] | Non Regulated Energy [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 9,847 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | 10,670 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Consolidation Elimination Entries [Member] | Transmission Investment [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
Consolidation Elimination Entries [Member] | All Others [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |  | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / us-gaap_StatementBusinessSegmentsAxis = us-gaap_CorporateAndOtherMember |
MGE [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 170,144 us-gaap_RegulatedAndUnregulatedOperatingRevenue / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  | 210,256 us-gaap_RegulatedAndUnregulatedOperatingRevenue / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |
Depreciation and amortization | (10,837)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  | (9,734)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |
Other operating expenses | (137,017)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / dei_LegalEntityAxis = us-gaap_SubsidiariesMember | [1] | (171,307)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / dei_LegalEntityAxis = us-gaap_SubsidiariesMember | [1]
Operating Income | 22,290 us-gaap_OperatingIncomeLoss / dei_LegalEntityAxis = us-gaap_SubsidiariesMember | [1] | 29,215 us-gaap_OperatingIncomeLoss / dei_LegalEntityAxis = us-gaap_SubsidiariesMember | [1]
Other income (deductions), net | 1,162 us-gaap_NonoperatingIncomeExpense / dei_LegalEntityAxis = us-gaap_SubsidiariesMember | [1] | 3,009 us-gaap_NonoperatingIncomeExpense / dei_LegalEntityAxis = us-gaap_SubsidiariesMember | [1]
Interest (expense) income, net | (5,141)us-gaap_InterestIncomeExpenseNet / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  | (4,581)us-gaap_InterestIncomeExpenseNet / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |
Income tax (provision) benefit | (9,776)us-gaap_IncomeTaxExpenseBenefit / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  | (14,924)us-gaap_IncomeTaxExpenseBenefit / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |
Net Income Including Noncontrolling Interest | 18,311 us-gaap_ProfitLoss / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  | 27,643 us-gaap_ProfitLoss / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |
Less Net Income Attributable to Noncontrolling Interest, net of tax | (6,553)us-gaap_NetIncomeLossAttributableToNoncontrollingInterest / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  | (6,510)us-gaap_NetIncomeLossAttributableToNoncontrollingInterest / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |
Net Income (Loss) | 11,758 us-gaap_NetIncomeLoss / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  | 21,133 us-gaap_NetIncomeLoss / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |
MGE [Member] | Electric [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 98,245 us-gaap_RegulatedAndUnregulatedOperatingRevenue / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | 98,858 us-gaap_RegulatedAndUnregulatedOperatingRevenue / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
MGE [Member] | Gas [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 69,933 us-gaap_RegulatedAndUnregulatedOperatingRevenue / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | 110,718 us-gaap_RegulatedAndUnregulatedOperatingRevenue / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
MGE [Member] | Non Regulated Energy [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 1,966 us-gaap_RegulatedAndUnregulatedOperatingRevenue / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | 680 us-gaap_RegulatedAndUnregulatedOperatingRevenue / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
MGE [Member] | Transmission Investment [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
MGE [Member] | Operating Segments [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 170,144 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  | 210,256 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |
MGE [Member] | Operating Segments [Member] | Electric [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 98,355 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | 98,970 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Depreciation and amortization | (7,332)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | (6,337)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Other operating expenses | (82,142)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember | [1] | (82,046)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember | [1]
Operating Income | 8,881 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember | [1] | 10,587 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember | [1]
Other income (deductions), net | 49 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember | [1] | 1,619 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember | [1]
Interest (expense) income, net | (2,819)us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | (2,205)us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Net Income Including Noncontrolling Interest | 6,111 us-gaap_ProfitLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | 10,001 us-gaap_ProfitLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Less Net Income Attributable to Noncontrolling Interest, net of tax | 0 us-gaap_NetIncomeLossAttributableToNoncontrollingInterest / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | 0 us-gaap_NetIncomeLossAttributableToNoncontrollingInterest / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
Net Income (Loss) | 6,111 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | 10,001 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
MGE [Member] | Operating Segments [Member] | Gas [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 72,653 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | 114,337 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Depreciation and amortization | (1,642)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | (1,563)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Other operating expenses | (64,138)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember | [1] | (100,450)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember | [1]
Operating Income | 6,873 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember | [1] | 12,324 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember | [1]
Other income (deductions), net | (12)us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember | [1] | (93)us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember | [1]
Interest (expense) income, net | (804)us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | (804)us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Net Income Including Noncontrolling Interest | 6,057 us-gaap_ProfitLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | 11,427 us-gaap_ProfitLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Less Net Income Attributable to Noncontrolling Interest, net of tax | 0 us-gaap_NetIncomeLossAttributableToNoncontrollingInterest / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | 0 us-gaap_NetIncomeLossAttributableToNoncontrollingInterest / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
Net Income (Loss) | 6,057 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | 11,427 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
MGE [Member] | Operating Segments [Member] | Non Regulated Energy [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 11,813 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | 11,350 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Depreciation and amortization | (1,863)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | (1,834)us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Other operating expenses | (3,414)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember | [1] | (3,212)mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember | [1]
Operating Income | 6,536 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember | [1] | 6,304 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember | [1]
Other income (deductions), net | 0 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember | [1] | 0 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember | [1]
Interest (expense) income, net | (1,518)us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | (1,572)us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Net Income Including Noncontrolling Interest | 5,018 us-gaap_ProfitLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | 4,732 us-gaap_ProfitLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Less Net Income Attributable to Noncontrolling Interest, net of tax | 0 us-gaap_NetIncomeLossAttributableToNoncontrollingInterest / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | 0 us-gaap_NetIncomeLossAttributableToNoncontrollingInterest / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
Net Income (Loss) | 5,018 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | 4,732 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
MGE [Member] | Operating Segments [Member] | Transmission Investment [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
Depreciation and amortization | 0 us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 0 us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
Other operating expenses | 0 mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember | [1] | 0 mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember | [1]
Operating Income | 0 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember | [1] | 0 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember | [1]
Other income (deductions), net | 1,125 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember | [1] | 1,483 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember | [1]
Interest (expense) income, net | 0 us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 0 us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
Net Income Including Noncontrolling Interest | 1,125 us-gaap_ProfitLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 1,483 us-gaap_ProfitLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
Less Net Income Attributable to Noncontrolling Interest, net of tax | 0 us-gaap_NetIncomeLossAttributableToNoncontrollingInterest / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 0 us-gaap_NetIncomeLossAttributableToNoncontrollingInterest / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
Net Income (Loss) | 1,125 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | 1,483 us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
MGE [Member] | Consolidation Elimination Entries [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | (12,677)us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  | (14,401)us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |
Depreciation and amortization | 0 us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  | 0 us-gaap_UtilitiesOperatingExpenseDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |
Other operating expenses | 12,677 mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember | [1] | 14,401 mgee_UtilitiesOperatingExpenseExcludingDepreciationAndAmortization / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember | [1]
Operating Income | 0 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember | [1] | 0 us-gaap_OperatingIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember | [1]
Other income (deductions), net | 0 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember | [1] | 0 us-gaap_NonoperatingIncomeExpense / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember | [1]
Interest (expense) income, net | 0 us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  | 0 us-gaap_InterestIncomeExpenseNet / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |
Net Income Including Noncontrolling Interest | 0 us-gaap_ProfitLoss / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  | 0 us-gaap_ProfitLoss / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |
Less Net Income Attributable to Noncontrolling Interest, net of tax | (6,553)us-gaap_NetIncomeLossAttributableToNoncontrollingInterest / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  | (6,510)us-gaap_NetIncomeLossAttributableToNoncontrollingInterest / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |
Net Income (Loss) | (6,553)us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |  | (6,510)us-gaap_NetIncomeLoss / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember |
MGE [Member] | Consolidation Elimination Entries [Member] | Electric [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 110 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |  | 112 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_ElectricMember |
MGE [Member] | Consolidation Elimination Entries [Member] | Gas [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 2,720 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |  | 3,619 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_GasMember |
MGE [Member] | Consolidation Elimination Entries [Member] | Non Regulated Energy [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | 9,847 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |  | 10,670 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_NonRegulatedEnergyMember |
MGE [Member] | Consolidation Elimination Entries [Member] | Transmission Investment [Member] |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Operating revenues | $ 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |  | $ 0 us-gaap_RegulatedAndUnregulatedOperatingRevenue / us-gaap_ConsolidationItemsAxis = us-gaap_IntersegmentEliminationMember / dei_LegalEntityAxis = us-gaap_SubsidiariesMember / us-gaap_StatementBusinessSegmentsAxis = mgee_TransmissionInvestmentMember |
[1] | *Amounts are shown net of the related tax expense, consistent with the presentation on the consolidated MGE Income Statement.

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