Summary of Significant Accounting Policies Property, Plant, and Equipment (Details)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Software | Minimum
Property, plant, and equipment
Estimated useful life	3 years
Software | Maximum
Property, plant, and equipment
Estimated useful life	15 years
WECI Wind Generating Facility | Maximum
Property, plant, and equipment
Estimated useful life	30 years
WECI Solar Generating Facility | Maximum
Property, plant, and equipment
Estimated useful life	35 years
PWGS | Minimum
Property, plant, and equipment
Estimated useful life	10 years
PWGS | Maximum
Property, plant, and equipment
Estimated useful life	45 years
ERGS | Minimum
Property, plant, and equipment
Estimated useful life	10 years
ERGS | Maximum
Property, plant, and equipment
Estimated useful life	55 years
WE
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	3.03%	3.03%	3.06%
WPS
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	2.92%	2.93%	2.67%
WG
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	2.61%	2.61%	2.47%
PGL
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	3.36%	3.13%	3.13%
NSG
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	2.49%	2.46%	2.43%
MERC
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	2.60%	2.60%	2.56%
MGU
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	2.87%	2.73%	2.75%
UMERC
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	3.01%	2.97%	3.01%