Schedule I - Income Statements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income statements
Other income, net	$ 177.7	$ 128.8	$ 133.2
Interest expense	726.9	515.1	471.1
Loss on debt extinguishment	0.0	0.0	36.3
Income before income taxes	1,536.3	1,732.6	1,498.8
Income tax benefit	(204.6)	(322.9)	(200.3)
Net income attributed to common shareholders	1,331.7	1,408.1	1,300.3
WEC Energy Group
Income statements
Operating expenses (income)	2.5	(1.6)	12.0
Equity earnings of subsidiaries	1,502.5	1,473.0	1,367.0
Other income, net	19.6	2.4	1.7
Interest expense	260.8	109.6	70.2
Loss on debt extinguishment	0.0	0.0	23.1
Income before income taxes	1,258.8	1,367.4	1,263.4
Income tax benefit	72.9	40.7	36.9
Net income attributed to common shareholders	$ 1,331.7	$ 1,408.1	$ 1,300.3