Schedule I - Cash Dividends Received from Subsidiaries (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
WECI
Notes to parent company financial statements
Return of capital from subsidiaries	$ 171.6	$ 363.7	$ 164.1
ATC Holding LLC
Notes to parent company financial statements
Return of capital from subsidiaries			32.0
Wispark
Notes to parent company financial statements
Return of capital from subsidiaries	3.6	9.2
WEC Energy Group
Notes to parent company financial statements
Cash dividends received from subsidiaries	935.7	1,035.6	795.7
Return of capital from subsidiaries	175.2	372.9	196.1
WEC Energy Group \| WE
Notes to parent company financial statements
Cash dividends received from subsidiaries	370.0	630.0	360.0
WEC Energy Group \| We Power
Notes to parent company financial statements
Cash dividends received from subsidiaries	192.8	158.5	217.9
WEC Energy Group \| WG
Notes to parent company financial statements
Cash dividends received from subsidiaries	171.0	60.0	30.0
WEC Energy Group \| WECI
Notes to parent company financial statements
Cash dividends received from subsidiaries	93.7	87.7	46.4
WEC Energy Group \| ATC Holding LLC
Notes to parent company financial statements
Cash dividends received from subsidiaries	86.8	74.9	106.4
WEC Energy Group \| UMERC
Notes to parent company financial statements
Cash dividends received from subsidiaries	21.0	17.0	0.0
WEC Energy Group \| Wispark
Notes to parent company financial statements
Cash dividends received from subsidiaries	0.4	7.5	0.0
WEC Energy Group \| Bluewater
Notes to parent company financial statements
Cash dividends received from subsidiaries	$ 0.0	$ 0.0	$ 35.0

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.

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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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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.

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