Summary of Significant Accounting Policies Property, Plant and Equipment (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
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
Software | Minimum
Property, plant, and equipment
Estimated useful life	3 years
Software | Maximum
Property, plant, and equipment
Estimated useful life	15 years
WE
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	3.09%	3.19%	3.11%
WPS
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	2.66%	2.63%	2.44%
WG
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	2.44%	2.33%	2.29%
PGL
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	3.12%	3.16%	3.20%
NSG
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	2.52%	2.48%	2.48%
MERC
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	2.58%	2.47%	2.33%
MGU
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	2.70%	2.67%	2.54%
UMERC
Property, plant, and equipment
Annual utility composite depreciation rate (as a percent)	2.94%	2.97%	2.87%