Contractual interest rate for funds borrowed, under the debt agreement.

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 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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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.

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- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3255-108585

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Amount of cash inflow from short-term debt classified as other.

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-Topic 230
-SubTopic 10
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Period of short-term debt issued. In 'PnYnMnDTnHnMnS' format, for example, P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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LONG-TERM DEBT (Details) - USD ($) $ in Millions		3 Months Ended
LONG-TERM DEBT (Details) - USD ($) $ in Millions	Mar. 30, 2020	Mar. 31, 2021	Mar. 31, 2020
Debt Instrument [Line Items]
Issuance of short-term loan		$ 0.0	$ 340.0
WEC Energy Group \| Term loan
Debt Instrument [Line Items]
Issuance of short-term loan	$ 340.0
Length of term loan	364 days
WEC Energy Group \| WEC Senior Notes 0.80% due 2024
Debt Instrument [Line Items]
Proceeds from issuance of debt		$ 600.0
Debt instrument stated interest rate percentage		0.80%