Property, Plant and Equipment, Net - MEC (Details) - MEC - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Plant, net	$ 19,808,000,000		$ 19,808,000,000		$ 19,201,000,000
Construction work-in-progress	972,000,000		972,000,000		1,100,000,000
Property, plant and equipment, net	20,780,000,000		20,780,000,000		20,301,000,000
Anticipated equity returns exceeding threshold
Property, Plant and Equipment [Line Items]
Regulatory liability, additions	115,000,000	$ 0	211,000,000	$ 0
Regulated
Property, Plant and Equipment [Line Items]
Utility plant in-service	27,688,000,000		27,688,000,000		26,571,000,000
Accumulated depreciation and amortization	(7,886,000,000)		(7,886,000,000)		(7,376,000,000)
Plant, net	19,802,000,000		19,802,000,000		19,195,000,000
Nonregulated
Property, Plant and Equipment [Line Items]
Accumulated depreciation and amortization	(1,000,000)		(1,000,000)		(1,000,000)
Plant, net	6,000,000		6,000,000		6,000,000
Nonregulated property, gross	7,000,000		$ 7,000,000		7,000,000
Nonregulated | Minimum
Property, Plant and Equipment [Line Items]
Useful life, other			20 years
Nonregulated | Maximum
Property, Plant and Equipment [Line Items]
Useful life, other			50 years
Electric Operations | Regulated
Property, Plant and Equipment [Line Items]
Generation	18,201,000,000		$ 18,201,000,000		17,397,000,000
Transmission	2,609,000,000		2,609,000,000		2,474,000,000
Distribution	4,777,000,000		$ 4,777,000,000		4,661,000,000
Electric Operations | Regulated | Minimum
Property, Plant and Equipment [Line Items]
Useful life, generation			20 years
Useful life, transmission			52 years
Useful life, distribution			20 years
Electric Operations | Regulated | Maximum
Property, Plant and Equipment [Line Items]
Useful life, generation			70 years
Useful life, transmission			75 years
Useful life, distribution			75 years
Natural Gas Processing Plant | Regulated
Property, Plant and Equipment [Line Items]
Distribution	$ 2,101,000,000		$ 2,101,000,000		$ 2,039,000,000
Natural Gas Processing Plant | Regulated | Minimum
Property, Plant and Equipment [Line Items]
Useful life, distribution			29 years
Natural Gas Processing Plant | Regulated | Maximum
Property, Plant and Equipment [Line Items]
Useful life, distribution			75 years