Business Segments (Schedule of Revenue, By Products and Services) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Revenues	$ 25,097	$ 23,868	$ 25,079
Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Revenues	22,570	21,687	22,798
Gas Utilities and Infrastructure
Segment Reporting Information [Line Items]
Revenues	2,022	1,653	1,770
Commercial Renewables
Segment Reporting Information [Line Items]
Revenues	476	502	487
Total Reportable Segments
Segment Reporting Information [Line Items]
Revenues	25,068	23,842	25,055
Retail Electric
Segment Reporting Information [Line Items]
Revenues	19,410	18,898	19,745
Retail Electric | Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Revenues	19,410	18,898	19,745
Wholesale Electric
Segment Reporting Information [Line Items]
Revenues	2,627	2,312	2,620
Wholesale Electric | Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Revenues	2,216	1,878	2,231
Wholesale Electric | Commercial Renewables
Segment Reporting Information [Line Items]
Revenues	411	434	389
Retail Natural Gas
Segment Reporting Information [Line Items]
Revenues	2,025	1,691	1,782
Retail Natural Gas | Gas Utilities and Infrastructure
Segment Reporting Information [Line Items]
Revenues	2,025	1,691	1,782
Other
Segment Reporting Information [Line Items]
Revenues	1,129	1,069	1,037
Other | Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Revenues	977	944	855
Other | Gas Utilities and Infrastructure
Segment Reporting Information [Line Items]
Revenues	87	57	84
Other | Commercial Renewables
Segment Reporting Information [Line Items]
Revenues	65	68	98
Operating Segments | Electric Utilities and Infrastructure
Segment Reporting Information [Line Items]
Revenues	22,603	21,720	22,831
Operating Segments | Gas Utilities and Infrastructure
Segment Reporting Information [Line Items]
Revenues	2,112	1,748	1,866
Operating Segments | Commercial Renewables
Segment Reporting Information [Line Items]
Revenues	476	502	487
Operating Segments | Total Reportable Segments
Segment Reporting Information [Line Items]
Revenues	$ 25,191	$ 23,970	$ 25,184