LONG-TERM DEBT (Details) - USD ($) $ in Millions	1 Months Ended
Jun. 30, 2021	May 31, 2021
WE 1.70% Debentures due June 15, 2028 \| Wisconsin Electric Power Company
Debt Instrument [Line Items]
Proceeds from issuance of debt	$ 300.0
Interest rate on long-term debt	1.70%
WE 2.95% Debentures due September 15, 2021 \| Wisconsin Electric Power Company
Debt Instrument [Line Items]
Interest rate on long-term debt	2.95%
Early repayment of long-term debt	$ 300.0
WEPCo Environmental Trust Bonds 1.578%, due 2035 \| WEPCo Environmental Trust Finance I, LLC
Debt Instrument [Line Items]
Proceeds from issuance of debt		$ 118.8
Interest rate on long-term debt		1.578%

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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
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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)
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The cash outflow to repay long-term debt that is not secured by collateral. Excludes repayments of tax exempt unsecured debt.

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