Property, Plant and Equipment, Net - MEC (Details) - MEC - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Public Utility, Property, Plant and Equipment [Line Items]
Utility plant in-service, net, excluding construction work-in-process	$ 21,212	$ 20,710
Property, plant and equipment, net	22,765	21,970
Revenue Sharing Arrangement, Anticipated Equity Returns Exceeding Threshold
Public Utility, Property, Plant and Equipment [Line Items]
Regulatory liability, additions	$ 81	$ 29	$ 296
Electric
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation and amortization rate	3.10%	3.30%	3.20%
Natural gas
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation and amortization rate	3.00%	2.80%	2.90%
Regulated assets
Public Utility, Property, Plant and Equipment [Line Items]
Utility plant in-service	$ 29,778	$ 28,545
Accumulated depreciation and amortization	(8,572)	(7,841)
Utility plant in-service, net, excluding construction work-in-process	21,206	20,704
Construction work- in-progress	1,553	1,260
Regulated assets | Electric
Public Utility, Property, Plant and Equipment [Line Items]
Generation	18,446	18,129
Transmission	3,029	2,834
Distribution	5,890	5,288
Regulated assets | Natural gas
Public Utility, Property, Plant and Equipment [Line Items]
Distribution	2,413	2,294
Nonregulated assets
Public Utility, Property, Plant and Equipment [Line Items]
Utility plant in-service, net, excluding construction work-in-process	$ 6	$ 6
Minimum | Regulated assets | Electric
Public Utility, Property, Plant and Equipment [Line Items]
Useful life, generation	20 years
Useful life, transmission	55 years
Useful life, distribution	15 years
Minimum | Regulated assets | Natural gas
Public Utility, Property, Plant and Equipment [Line Items]
Useful life, distribution	30 years
Minimum | Nonregulated assets
Public Utility, Property, Plant and Equipment [Line Items]
Useful life, other	20 years
Maximum | Regulated assets | Electric
Public Utility, Property, Plant and Equipment [Line Items]
Useful life, generation	62 years
Useful life, transmission	80 years
Useful life, distribution	80 years
Maximum | Regulated assets | Natural gas
Public Utility, Property, Plant and Equipment [Line Items]
Useful life, distribution	75 years
Maximum | Nonregulated assets
Public Utility, Property, Plant and Equipment [Line Items]
Useful life, other	50 years