Segment Information (Schedule of Revenues By Geographic Area Based On The Location of Customers) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Revenue	$ 38,469	$ 37,925	$ 39,350
North America
Segment Reporting Information [Line Items]
Revenue	32,588	32,272	32,673
United States
Segment Reporting Information [Line Items]
Revenue	31,654	31,194	31,775
Other North America
Segment Reporting Information [Line Items]
Revenue	934	1,078	898
Europe
Segment Reporting Information [Line Items]
Revenue	2,675	2,846	2,836
Asia Pacific
Segment Reporting Information [Line Items]
Revenue	1,269	1,292	1,739
Africa Middle East
Segment Reporting Information [Line Items]
Revenue	1,703	1,249	1,785
South America
Segment Reporting Information [Line Items]
Revenue	$ 234	$ 266	$ 317