Schedule I - Cash Dividends Received from Subsidiaries (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
WECI
Notes to parent company financial statements
Return of capital from subsidiaries	$ 363.7	$ 164.1	$ 583.2
ATC Holding LLC
Notes to parent company financial statements
Return of capital from subsidiaries		32.0	19.6
Wispark
Notes to parent company financial statements
Return of capital from subsidiaries	9.2
WEC Energy Group
Notes to parent company financial statements
Cash dividends received from subsidiaries	1,035.6	795.7	898.1
Return of capital from subsidiaries	372.9	196.1	602.8
WEC Energy Group \| WE
Notes to parent company financial statements
Cash dividends received from subsidiaries	630.0	360.0	395.0
WEC Energy Group \| We Power
Notes to parent company financial statements
Cash dividends received from subsidiaries	158.5	217.9	240.9
WEC Energy Group \| WECI
Notes to parent company financial statements
Cash dividends received from subsidiaries	87.7	46.4	33.6
WEC Energy Group \| ATC Holding LLC
Notes to parent company financial statements
Cash dividends received from subsidiaries	74.9	106.4	112.6
WEC Energy Group \| WG
Notes to parent company financial statements
Cash dividends received from subsidiaries	60.0	30.0	70.0
WEC Energy Group \| UMERC
Notes to parent company financial statements
Cash dividends received from subsidiaries	17.0	0.0	46.0
WEC Energy Group \| Wispark
Notes to parent company financial statements
Cash dividends received from subsidiaries	7.5	0.0	0.0
WEC Energy Group \| Bluewater
Notes to parent company financial statements
Cash dividends received from subsidiaries	$ 0.0	$ 35.0	$ 0.0

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- Definition

This element represents disclosure of the aggregate cash dividends paid to the entity by consolidated subsidiaries.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(b))
-URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e24072-122690

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- Definition

Amount of distribution received from equity method investee for return of investment, classified as investing activities. Excludes distribution for return on investment, classified as operating activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 21D
-URI https://asc.fasb.org/extlink&oid=126954810&loc=SL94080555-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3179-108585

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