Schedule I - Statements of Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statements of comprehensive income
Net income attributed to common shareholders	$ 1,408.1	$ 1,300.3	$ 1,199.9
Other comprehensive income (loss), net of tax	(3.6)	3.6	(2.7)
Comprehensive income attributed to common shareholders	1,404.5	1,303.9	1,197.2
Derivatives accounted for as cash flow hedges
Net derivative gain (loss), net of tax expense (benefit) of $—, $0.2, and $(1.6), respectively	0.0	0.6	(4.3)
Reclassification of realized net derivative (gain) loss to net income, net of tax	(0.3)	0.9	1.5
Defined benefit plans
Pension and OPEB adjustments arising during the period, net of tax expense (benefit) of $(1.3), $0.7, and $(0.2), respectively	(3.5)	1.7	(0.5)
Amortization of pension and OPEB costs included in net periodic benefit cost, net of tax	0.2	0.4	0.6
Defined benefit plans, net	(3.3)	2.1	0.1
WEC Energy Group
Statements of comprehensive income
Net income attributed to common shareholders	1,408.1	1,300.3	1,199.9
Other comprehensive income (loss) from subsidiaries, net of tax	(2.7)	1.4	0.2
Other comprehensive income (loss), net of tax	(3.6)	3.6	(2.7)
WEC Energy Group | Derivatives accounted for as cash flow hedges
Derivatives accounted for as cash flow hedges
Net derivative gain (loss), net of tax expense (benefit) of $—, $0.2, and $(1.6), respectively	0.0	0.6	(4.3)
Reclassification of realized net derivative (gain) loss to net income, net of tax	(0.3)	0.9	1.5
Cash flow hedges, net	(0.3)	1.5	(2.8)
WEC Energy Group | Defined benefit plans
Defined benefit plans
Pension and OPEB adjustments arising during the period, net of tax expense (benefit) of $(1.3), $0.7, and $(0.2), respectively	(0.8)	0.4	(0.4)
Amortization of pension and OPEB costs included in net periodic benefit cost, net of tax	0.2	0.3	0.3
Defined benefit plans, net	$ (0.6)	$ 0.7	$ (0.1)