XML 111 R95.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Short-Term Debt and Lines of Credit - Credit Facilities (Details) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2017 USD ($) extension | Dec. 31, 2016 USD ($)
Line of Credit Facility [Line Items] |  |
Short-term credit capacity | $ 2,800.0 |
Letters of credit issued inside credit facilities | 7.9 |
Commercial paper | 1,444.6 | $ 860.2
Available capacity under existing agreements | 1,347.5 |
WEC Energy Group |  |
Line of Credit Facility [Line Items] |  |
Commercial paper | 494.8 | $ 321.8
WEC Energy Group | Credit facility maturing October 2022 |  |
Line of Credit Facility [Line Items] |  |
Short-term credit capacity | $ 1,200.0 |
Number of extensions available on a credit facility | extension | 2 |
Length of credit facility extension | 1 year |
WE | Credit facility maturing October 2022 |  |
Line of Credit Facility [Line Items] |  |
Short-term credit capacity | $ 500.0 |
Number of extensions available on a credit facility | extension | 2 |
Length of credit facility extension | 1 year |
WPS | Credit facility maturing December 2020 |  |
Line of Credit Facility [Line Items] |  |
Short-term credit capacity | $ 400.0 |
Number of extensions available on a credit facility | extension | 2 |
Length of credit facility extension | 1 year |
WG | Credit facility maturing October 2022 |  |
Line of Credit Facility [Line Items] |  |
Short-term credit capacity | $ 350.0 |
Number of extensions available on a credit facility | extension | 2 |
Length of credit facility extension | 1 year |
PGL | Credit facility maturing October 2022 |  |
Line of Credit Facility [Line Items] |  |
Short-term credit capacity | $ 350.0 |
Number of extensions available on a credit facility | extension | 2 |
Length of credit facility extension | 1 year |
Commercial paper |  |
Line of Credit Facility [Line Items] |  |
Commercial paper | $ 1,444.6 |

X
- Definition Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(19)(a)(3)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(13)(2)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_CommercialPaper
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. + References No definition available. + Details
Name: | us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Length of time a credit facility can be extended. + References No definition available. + Details
Name: | wec_Lengthofcreditfacilityextension
Namespace Prefix: | wec_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of extensions available on credit facility + References No definition available. + Details
Name: | wec_Numberofextensionsavailableonacreditfacility
Namespace Prefix: | wec_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_ConsolidatedEntitiesAxis=us-gaap_ParentCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=wec_CreditfacilitymaturingOctober2022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_WisconsinelectricMember
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: | us-gaap_CreditFacilityAxis=wec_CreditfacilitymaturingDecember2020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=wec_WisconsinGasMember
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_ShortTermDebtTypeAxis=us-gaap_CommercialPaperMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |