XML 27 R37.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Chattel Paper Agreements (Details-1) (USD $) | 3 Months Ended |
--- | --- | ---
Mar. 31, 2015 | Dec. 31, 2014
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] |  |
Cumulative effect of new accounting guidance, retained earnings |  | $ (142,000)mgee_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption
Chattel Paper Agreements [Member] |  |
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] |  |
Repurchase agreement, maximum exposure | 10,000,000 mgee_SecuritiesSoldUnderAgreementsToRepurchaseMaximumExposure / us-gaap_FinancialInstrumentAxis = us-gaap_RepurchaseAgreementsMember |
Repurchase-to-Maturity Transactions, loans due | 4,266,000 mgee_SecuritiesSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement / us-gaap_FinancialInstrumentAxis = us-gaap_RepurchaseAgreementsMember |
Cumulative effect of new accounting guidance, retained earnings |  | (100,000)mgee_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption / us-gaap_FinancialInstrumentAxis = us-gaap_RepurchaseAgreementsMember
2015 [Member] | Chattel Paper Agreements [Member] |  |
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] |  |
Repurchase-to-Maturity Transactions, loans due | 383,000 mgee_SecuritiesSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement / us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis = mgee_MaturityUpToOneYearMember / us-gaap_FinancialInstrumentAxis = us-gaap_RepurchaseAgreementsMember |
2016 [Member] | Chattel Paper Agreements [Member] |  |
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] |  |
Repurchase-to-Maturity Transactions, loans due | 950,000 mgee_SecuritiesSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement / us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis = mgee_MaturityOneToTwoYearsMember / us-gaap_FinancialInstrumentAxis = us-gaap_RepurchaseAgreementsMember |
2017 [Member] | Chattel Paper Agreements [Member] |  |
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] |  |
Repurchase-to-Maturity Transactions, loans due | 552,000 mgee_SecuritiesSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement / us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis = mgee_MaturityTwoToThreeYearsMember / us-gaap_FinancialInstrumentAxis = us-gaap_RepurchaseAgreementsMember |
2018 [Member] | Chattel Paper Agreements [Member] |  |
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] |  |
Repurchase-to-Maturity Transactions, loans due | 540,000 mgee_SecuritiesSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement / us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis = mgee_MaturityThreeToFourYearsMember / us-gaap_FinancialInstrumentAxis = us-gaap_RepurchaseAgreementsMember |
Thereafter [Member] | Chattel Paper Agreements [Member] |  |
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] |  |
Repurchase-to-Maturity Transactions, loans due | 1,841,000 mgee_SecuritiesSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement / us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis = mgee_MaturityOverFourYearsMember / us-gaap_FinancialInstrumentAxis = us-gaap_RepurchaseAgreementsMember |
Minimum [Member] | Chattel Paper Agreements [Member] |  |
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] |  |
MGE guarantee to the financial institution, term | 1 year |
Maximum [Member] | Chattel Paper Agreements [Member] |  |
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] |  |
MGE guarantee to the financial institution, term | 10 years |

X
- Definition Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption. + References No definition available. + Details
Name: | mgee_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption
Namespace Prefix: | mgee_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, before effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and elected not to be offset. + References No definition available. + Details
Name: | mgee_SecuritiesSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement
Namespace Prefix: | mgee_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the repurchase agreement with recourse. + References No definition available. + Details
Name: | mgee_SecuritiesSoldUnderAgreementsToRepurchaseMaximumExposure
Namespace Prefix: | mgee_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Describes the approximate term of the repurchase agreement. + References No definition available. + Details
Name: | mgee_SecuritiesSoldUnderAgreementsToRepurchaseTerm
Namespace Prefix: | mgee_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | mgee_TransferOfCertainFinancialAssetsAccountedForAsSecuredBorrowingsLineItems
Namespace Prefix: | mgee_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis=mgee_MaturityOneToTwoYearsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis=mgee_MaturityOverFourYearsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis=mgee_MaturityThreeToFourYearsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis=mgee_MaturityTwoToThreeYearsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis=mgee_MaturityUpToOneYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_RepurchaseAgreementsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |