XML 94 R73.htm IDEA: XBRL DOCUMENT
v3.25.4

Regulatory Assets and Liabilities - Regulatory Assets (Details-1) - USD ($) $ in Thousands | Dec. 31, 2025 | Dec. 31, 2024
--- | --- | ---
Regulatory Asset [Line Items] |  |
Regulatory Asset | $ 51,637 | $ 45,286
Asset Retirement Obligation [Member] |  |
Regulatory Asset [Line Items] |  |
Regulatory Asset | 9,592 | 6,813
Deferred Bad Debt Expense [Member] |  |
Regulatory Asset [Line Items] |  |
Regulatory Asset | 2,250 | 5,200
Debt Related Costs [Member] |  |
Regulatory Asset [Line Items] |  |
Regulatory Asset | 6,077 | 6,538
Derivatives [Member] |  |
Regulatory Asset [Line Items] |  |
Regulatory Asset | 1,595 | 0
Leases [Member] |  |
Regulatory Asset [Line Items] |  |
Regulatory Asset | 5,031 | 4,598
Deferred Pension And Other Postretirement Costs [Member] |  |
Regulatory Asset [Line Items] |  |
Regulatory Asset | 0 | 642
Tax Recovery Related to AFUDC Equity [Member] |  |
Regulatory Asset [Line Items] |  |
Regulatory Asset | 14,859 | 13,440
Electric Transmission Costs [Member] |  |
Regulatory Asset [Line Items] |  |
Regulatory Asset | 2,258 | 1,216
West Riverside Regulatory Asset [Member] |  |
Regulatory Asset [Line Items] |  |
Regulatory Asset | 3,453 | 1,276
Other Regulatory Asset [Member] |  |
Regulatory Asset [Line Items] |  |
Regulatory Asset | $ 6,522 | $ 5,563

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_RegulatoryAssetLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 340 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478742/980-340-50-1 + Details
Name: | us-gaap_RegulatoryAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_AssetRetirementObligationCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=mgee_DeferredBadDebtExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=mgee_DebtRelatedCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_DeferredDerivativeGainLossMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=mgee_LeaseRegulatoryAssetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=mgee_DeferredPensionAndOtherPostretirementCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=mgee_TaxRecoveryAfudcEquityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=mgee_ElectricTransmissionCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=mgee_WestRiversideRegulatoryAssetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=mgee_OtherRegulatoryAssetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |