Property, Plant and Equipment, Net - MEC (Details) - MEC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Plant, net	$ 20,002		$ 20,301
Construction work-in-progress	979		790
Property, plant and equipment, net	20,981		21,091
Anticipated equity returns exceeding threshold
Property, Plant and Equipment [Line Items]
Regulatory liability, additions	20	$ 42
Regulated
Property, Plant and Equipment [Line Items]
Utility plant in-service	28,206		28,319
Accumulated depreciation and amortization	(8,210)		(8,024)
Plant, net	19,996		20,295
Nonregulated
Property, Plant and Equipment [Line Items]
Plant, net	$ 6		6
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	$ 18,385		18,582
Transmission	2,672		2,662
Distribution	$ 4,983		4,931
Electric Operations | Regulated | Minimum
Property, Plant and Equipment [Line Items]
Useful life, generation	20 years
Useful life, transmission	55 years
Useful life, distribution	15 years
Electric Operations | Regulated | Maximum
Property, Plant and Equipment [Line Items]
Useful life, generation	62 years
Useful life, transmission	80 years
Useful life, distribution	80 years
Natural Gas Processing Plant | Regulated
Property, Plant and Equipment [Line Items]
Distribution	$ 2,166		$ 2,144
Natural Gas Processing Plant | Regulated | Minimum
Property, Plant and Equipment [Line Items]
Useful life, distribution	30 years
Natural Gas Processing Plant | Regulated | Maximum
Property, Plant and Equipment [Line Items]
Useful life, distribution	75 years