Long-Term Debt - Issuances and Redemptions (Details) - USD ($) $ in Millions		1 Months Ended						3 Months Ended	12 Months Ended
	Feb. 07, 2024	Dec. 31, 2024	Nov. 30, 2024	Oct. 31, 2024	Sep. 30, 2024	May 31, 2024	Mar. 31, 2024	Jun. 30, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Long-term debt
Gain on Extinguishment of Debt									$ 23.1	$ 0.5	$ 0.0
WE
Long-term debt
DOE Federal Loan Guarantee		$ 2,500.0							2,500.0
Unsecured debt		3,935.0							3,935.0	3,285.0
WG
Long-term debt
Unsecured debt		$ 840.0							$ 840.0	790.0
5.00% WE Debentures due 05/15/2029 | WE
Long-term debt
Issuance of debt						$ 350.0
Interest rate						5.00%
4.60% WE Debentures due 10/01/2034 | WE
Long-term debt
Issuance of debt					$ 300.0
Interest rate					4.60%
5.05% WE Debentures due 10/01/2054 | WE
Long-term debt
Issuance of debt					$ 300.0
Interest rate					5.05%
2.05% WE Debentures due December 2024 | WE
Long-term debt
Interest rate		2.05%							2.05%
Repayment of long-term debt		$ 300.0
4.55% WPS Senior Notes due 12/01/2029 | WPS
Long-term debt
Issuance of debt		$ 300.0
Interest rate		4.55%							4.55%
4.86% WG Debentures due 11/01/2029 | WG
Long-term debt
Issuance of debt				$ 100.0
Interest rate				4.86%
5.18% WG Debentures due 11/01/2034 | WG
Long-term debt
Issuance of debt				$ 100.0
Interest rate				5.18%
2.38% WG Debentures due November 2024 | WG
Long-term debt
Interest rate			2.38%
Repayment of long-term debt			$ 150.0
2.64% PGL Bonds due November 2024 | PGL
Long-term debt
Interest rate			2.64%
Redemption of secured debt			$ 75.0
4.85% MGU Senior Notes due 11/01/2029 | MGU
Long-term debt
Issuance of debt				$ 10.0
Interest rate				4.85%
5.23% MGU Senior Notes due 11/01/2034 | MGU
Long-term debt
Issuance of debt				$ 15.0
Interest rate				5.23%
5.41% Bluewater Senior Notes due 11/01/2041 | Bluewater
Long-term debt
Issuance of debt				$ 25.0
Interest rate				5.41%
5.73% WECI Energy Holding III LLC Senior Notes Due 12/31/2039 | WECI Energy Holding III
Long-term debt
Issuance of debt		$ 488.7
Interest rate		5.73%							5.73%
WEC Energy Group
Long-term debt
Gain on Extinguishment of Debt									$ 23.1	$ 0.0	$ 0.0
WEC Energy Group | WEC Energy Group junior notes due 2067
Long-term debt
Interest rate										7.75%
Unsecured debt	$ 500.0					$ 377.9				$ 500.0
Repayment of long-term debt	115.2					18.7
Extinguishment of debt	122.1	$ 358.9				19.0
Gain on Extinguishment of Debt	$ 6.4					$ 0.2
WEC Energy Group | WEC 0.80% Senior Notes $600M due March 15, 2024
Long-term debt
Interest rate							0.80%
Repayment of long-term debt							$ 600.0
WEC Energy Group | 2024A Junior Notes due June 15, 2055
Long-term debt
Issuance of debt		$ 254.0
Interest rate		6.69%							6.69%
WEC Energy Group | 2024B Junior Notes due June 15, 2055
Long-term debt
Issuance of debt		$ 496.0
Interest rate		6.74%							6.74%
WEC Energy Group | WEC 5.60% Senior Notes due September 12, 2026
Long-term debt
Interest rate		5.60%							5.60%
Unsecured debt		$ 600.0							$ 600.0
Repayment of long-term debt		380.9
Extinguishment of debt		250.0
Gain on Extinguishment of Debt		$ 16.5
WEC Energy Group | WEC 1.80% Senior Notes due October 15, 2030
Long-term debt
Interest rate		1.80%							1.80%
Unsecured debt		$ 450.0							$ 450.0
Repayment of long-term debt		380.9
Extinguishment of debt		150.0
Gain on Extinguishment of Debt		$ 16.5
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2027
Long-term debt
Issuance of debt								$ 862.5
Interest rate								4.375%
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2029
Long-term debt
Issuance of debt								$ 862.5
Interest rate								4.375%