Property, Plant and Equipment (Components of PP&E) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Electric generation, distribution assets and other	$ 25,552	$ 26,707
Accumulated depreciation	(8,486)	(8,472)
Property, Plant and Equipment, Net	17,066	18,235
Electric generation and distribution facilities
Property, Plant and Equipment [Line Items]
Electric generation, distribution assets and other	$ 22,909	24,239
Electric generation and distribution facilities | Minimum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Electric generation and distribution facilities | Maximum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	39 years
Other buildings
Property, Plant and Equipment [Line Items]
Electric generation, distribution assets and other	$ 1,552	1,507
Other buildings | Minimum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Other buildings | Maximum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	51 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Electric generation, distribution assets and other	$ 356	333
Furniture and Fixtures [Member] | Minimum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Furniture and Fixtures [Member] | Maximum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	30 years
Other
Property, Plant and Equipment [Line Items]
Electric generation, distribution assets and other	$ 735	$ 628
Other | Minimum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	1 year
Other | Maximum
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	39 years