XML 85 R72.htm IDEA: XBRL DOCUMENT
v3.8.0.1

REGULATORY ENVIRONMENT (Details) $ in Millions | 1 Months Ended |
--- | --- | ---
Oct. 31, 2017 USD ($) MW | Sep. 30, 2017 USD ($) utility Assurance | Jan. 31, 2017 | Oct. 31, 2016 USD ($) | Apr. 30, 2015 USD ($) | Jun. 30, 2017 USD ($)
WE | Public Service Commission of Wisconsin (PSCW) | 2018 and 2019 rates |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |
Approved return on equity (as a percent) |  | 10.20% |  |  |  |
WG | Public Service Commission of Wisconsin (PSCW) | 2018 and 2019 rates |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |
Approved return on equity (as a percent) |  | 10.30% |  |  |  |
WPS | Public Service Commission of Wisconsin (PSCW) | 2018 and 2019 rates |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |
Approved return on equity (as a percent) |  | 10.00% |  |  |  |
Authorized revenue requirement for the ReACT project |  | $ 275.0 |  |  |  |
AFUDC |  | 51.0 |  |  |  |
Estimated cost of the ReACT project, excluding AFUDC |  | $ 342.0 |  |  |  |
WE, WG, and WPS | Public Service Commission of Wisconsin (PSCW) | Natural gas storage facilities in Michigan |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |
Percentage of natural gas storage needs provided by the facilities |  |  | 33.33% |  |  |
WE, WG, and WPS | Public Service Commission of Wisconsin (PSCW) | 2018 and 2019 rates |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |
Number of utilities with earnings sharing mechanism | utility |  | 3 |  |  |  |
Percentage of first 50 basis points of additional utility earnings shared with customers |  | 50.00% |  |  |  |
Return on equity in excess of authorized amount (as a percent) |  | 0.50% |  |  |  |
PGL | Illinois Commerce Commission (ICC) |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |
Amount of assurance that PGL's QIP rider costs will be recoverable | Assurance |  | 0 |  |  |  |
MERC | Minnesota Public Utilities Commission (MPUC) | 2018 rates | Natural gas rates | Subsequent event |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |
Requested rate increase | $ 12.6 |  |  |  |  |
Requested rate increase (as a percent) | 5.05% |  |  |  |  |
Requested return on equity (as a percent) | 10.30% |  |  |  |  |
Requested common equity component average (as a percent) | 50.90% |  |  |  |  |
MERC | Minnesota Public Utilities Commission (MPUC) | 2016 rates | Natural gas rates |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |
Approved return on equity (as a percent) |  |  |  | 9.11% |  |
Approved rate increase |  |  |  | $ 6.8 |  |
Approved rate increase (as a percent) |  |  |  | 3.00% |  |
Approved common equity component average (as a percent) |  |  |  | 50.32% |  |
Number of years decoupling mechanism authorized for use |  |  |  | 3 years |  |
Interim rate refund |  |  |  |  |  | $ 4.1
UMERC | Subsequent event |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |
Capacity of natural gas-fired generation facility (in megawatts) | MW | 180 |  |  |  |  |
UMERC | Michigan Public Service Commission (MPSC) | Subsequent event |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |
Term of electric power purchase agreement (in years) | 20 years |  |  |  |  |
Capacity of natural gas-fired generation facility (in megawatts) | MW | 180 |  |  |  |  |
Estimated cost of constructing a power plant | $ 265.7 |  |  |  |  |
Estimated cost of constructing a power plant, including AFUDC | $ 277.0 |  |  |  |  |
Portion of the power plant costs recoverable from Tilden Mining Company (as a percent) | 50.00% |  |  |  |  |
Portion of the power plant costs recoverable from utility customers (as a percent) | 50.00% |  |  |  |  |
UMERC | Michigan Public Service Commission (MPSC) | 2015 rates | Electric rates |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |
Approved return on equity (as a percent) |  |  |  |  | 10.20% |
Approved rate increase |  |  |  |  | $ 4.0 |
Approved common equity component average (as a percent) |  |  |  |  | 50.48% |
Period of rate implementation (in years) |  |  |  |  | 3 years |

X
- Definition Amount capitalized of allowance for funds used during construction. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 835 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6501569&loc=d3e55921-110430 + Details
Name: | us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionCapitalizedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of public utility's approved equity to capital, including debt and equity. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesApprovedEquityCapitalStructurePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of public utility's approved rate increase (decrease) by regulatory agency. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Percentage of public utility's approved rate increase (decrease) by regulatory agency. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesApprovedRateIncreaseDecreasePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of public utility's approved return on equity. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesApprovedReturnOnEquityPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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_PublicUtilitiesGeneralDisclosuresLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of public utility's requested equity to capital, including debt and equity. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedEquityCapitalStructurePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of public utility's requested rate increase (decrease) with regulatory agency. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedRateIncreaseDecreaseAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Percentage of public utility's requested rate increase (decrease) with regulatory agency. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedRateIncreaseDecreasePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of public utility's requested return on equity. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedReturnOnEquityPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Actual return on equity (ROE) in excess of authorized amount, for which a percentage will be returned to customers. + References No definition available. + Details
Name: | wec_ActualROEInExcessOfAuthorizedAmount
Namespace Prefix: | wec_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of assurance that the costs incurred under PGL's Qualifying Infrastructure Plant rider will be recoverable. + References No definition available. + Details
Name: | wec_AmountOfAssuranceQIPRiderCostsRecoverable
Namespace Prefix: | wec_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The authorized revenue requirement for ReACT that was used to calculate the ReACT deferral. + References No definition available. + Details
Name: | wec_AuthorizedRevenueRequirementForReACT
Namespace Prefix: | wec_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The capacity (in megawatts) of a natural gas-fired generation facility. + References No definition available. + Details
Name: | wec_CapacityOfNaturalGasFiredGenerationFacility
Namespace Prefix: | wec_
Data Type: | num:powerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cost of constructing a power plant. + References No definition available. + Details
Name: | wec_CostOfConstructingPowerPlant
Namespace Prefix: | wec_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cost of constructing a power plant, including allowance for funds used during construction (AFUDC). + References No definition available. + Details
Name: | wec_CostOfConstructingPowerPlantWithAFUDC
Namespace Prefix: | wec_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The total cost of WPS's ReACT project, excluding AFUDC. + References No definition available. + Details
Name: | wec_CostOfReACTProjectExcludingAFUDC
Namespace Prefix: | wec_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Term (in years) of an electric power purchase agreement with the Tilden Mining Company. + References No definition available. + Details
Name: | wec_ElectricPowerPurchaseAgreementTerm
Namespace Prefix: | wec_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The interim rate refund that must be provided to customers. + References No definition available. + Details
Name: | wec_InterimRateRefund
Namespace Prefix: | wec_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Number of utilities that agreed to employ an earnings sharing mechanism. + References No definition available. + Details
Name: | wec_NumberOfUtilitiesWithEarningsSharingMechanism
Namespace Prefix: | wec_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of years a decoupling mechanism was authorized for use in a rate order. + References No definition available. + Details
Name: | wec_NumberOfYearsDecouplingMechanismApproval
Namespace Prefix: | wec_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of first 50 basis points of additional utility earnings that will be shared with customers. + References No definition available. + Details
Name: | wec_PercentageOfFirst50BasisPointsSharedWithCustomers
Namespace Prefix: | wec_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of the company's Wisconsin natural gas storage needs provided by the natural gas storage facility. + References No definition available. + Details
Name: | wec_PercentageOfStorageNeedsProvidedByStorageFacility
Namespace Prefix: | wec_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The portion (as a percent) of the costs to construct a power plant that will be recovered from the Tilden Mining Company. + References No definition available. + Details
Name: | wec_PortionOfPowerPlantCostsRecoveryFromTildenMiningCompany
Namespace Prefix: | wec_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The portion (as a percent) of the costs to construct a power plant that will be recovered from utility customers. + References No definition available. + Details
Name: | wec_PortionOfPowerPlantCostsRecoveryFromUtilityCustomers
Namespace Prefix: | wec_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the period over which rates will be implemented. + References No definition available. + Details
Name: | wec_RateImplementationPeriod
Namespace Prefix: | wec_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=wec_WisconsinElectricPowerCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=wec_PublicServiceCommissionOfWisconsinPSCWMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | wec_RateCaseYearAxis=wec_Rate2018And2019Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_WisconsinGasLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_WisconsinPublicServiceCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_WisconsinElectricPowerCompanyWisconsinGasLLCWisconsinPublicServiceCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=wec_MichiganNaturalGasStorageFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_ThePeoplesGasLightAndCokeCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=wec_IllinoisCommerceCommissionICCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_MinnesotaEnergyResourcesCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=wec_MinnesotaPublicUtilitiesCommissionMPUCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | wec_RateCaseYearAxis=wec_Rates2018Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilitiesRegulatoryProceedingAxis=wec_NaturalGasRateRequestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | wec_RateCaseYearAxis=wec_Rates2016Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_UpperMichiganEnergyResourcesCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=wec_MichiganPublicServiceCommissionMPSCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | wec_RateCaseYearAxis=wec_Rates2015Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilitiesRegulatoryProceedingAxis=wec_ElectricRateRequestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |