Property, Plant and Equipment, Net - MEC (Details) - MEC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Plant, net	$ 20,642		$ 20,710
Construction work-in-progress	1,443		1,260
Property, plant and equipment, net	22,085		21,970
Anticipated equity returns exceeding threshold
Property, Plant and Equipment [Line Items]
Regulatory liability, additions	0	$ 20
Regulated
Property, Plant and Equipment [Line Items]
Utility plant in-service	28,654		28,545
Accumulated depreciation and amortization	(8,018)		(7,841)
Plant, net	20,636		20,704
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	$ 18,132		18,129
Transmission	2,853		2,834
Distribution	$ 5,352		5,288
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	$ 2,317		$ 2,294
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