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Short-Term Debt and Lines of Credit - Credit Facilities (Details) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2018 USD ($) extension | Dec. 31, 2017 USD ($)
Line of Credit Facility [Line Items] |  |
Short-term credit capacity | $ 2,800.0 |
Commercial paper | 1,440.1 | $ 1,444.6
Available capacity under existing agreements | 1,356.9 |
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 October 2022 |  |
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 |
WEC Energy Group |  |
Line of Credit Facility [Line Items] |  |
Commercial paper | $ 548.4 | 494.8
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 |
Letter of Credit |  |
Line of Credit Facility [Line Items] |  |
Letters of credit issued inside credit facilities | $ 3.0 |
Commercial paper |  |
Line of Credit Facility [Line Items] |  |
Commercial paper | $ 1,440.1 | $ 1,444.6

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- 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://fasb.org/us-gaap/role/ref/legacyRef -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 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -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://fasb.org/us-gaap/role/ref/legacyRef -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 + Details
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- 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://fasb.org/us-gaap/role/ref/legacyRef -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
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