Long-Term Debt - Debt Maturing Within One Year (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Long-term debt maturing within one year
2023	$ 808.5
2024	1,239.6
2025	1,685.5
2026	126.8
2027	1,230.7
Thereafter	10,468.7
Long-term Debt, Gross	15,559.8	$ 13,652.6
WEC Energy Group
Long-term debt maturing within one year
2023	700.0
2024	600.0
2025	620.0
2026	0.0
2027	900.0
Thereafter	$ 1,650.0
WEC 0.55% Senior Notes due September 15, 2023 \| WEC Energy Group
Long-term debt maturing within one year
Interest rate	0.55%
Principal amount of unsecured debt	$ 700.0
WEPCo Environmental Trust Bonds 1.578%, due 2035 \| WEPCo Environmental Trust Finance I, LLC
Long-term debt maturing within one year
Interest rate	1.58%
Principal amount of unsecured debt	$ 8.9
3.76% Bluewater Gas Storage senior notes \| Bluewater Gas Storage
Long-term debt maturing within one year
Interest rate	3.76%
Principal amount of senior notes	$ 2.8
4.91% We Power subsidiaries notes - PWGS \| We Power
Long-term debt maturing within one year
Interest rate	4.91%
Principal amount of secured debt	$ 7.6
5.209% We Power subsidiaries notes - ERGS \| We Power
Long-term debt maturing within one year
Interest rate	5.209%
Principal amount of secured debt	$ 14.7
4.673% We Power subsidiaries notes - ERGS \| We Power
Long-term debt maturing within one year
Interest rate	4.673%
Principal amount of secured debt	$ 11.1
6.00% We Power subsidiaries notes - PWGS \| We Power
Long-term debt maturing within one year
Interest rate	6.00%
Principal amount of secured debt	$ 6.6
2.75% WECI Wind Holding I senior notes \| WECI Wind Holding I
Long-term debt maturing within one year
Interest rate	2.75%
Principal amount of senior notes	$ 42.0
6.38% WECI Wind Holding II LLC Senior Notes Due 2031 \| WECI Wind Holding II
Long-term debt maturing within one year
Interest rate	6.38%
Principal amount of senior notes	$ 14.8

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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