Segment And Geographic Information (Geographic Information) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Information
Revenues	$ 22,978	$ 21,695	$ 25,190	$ 24,072	$ 25,939	$ 24,683	$ 27,284	$ 23,650	$ 93,935	$ 101,556	$ 85,249
Long-Lived Assets	10,508				9,933				10,508	9,933
UNITED STATES
Segment Information
Revenues									38,783	43,272	35,396
Long-Lived Assets	6,660				6,322				6,660	6,322
Switzerland [Member]
Segment Information
Revenues									19,898	21,821	18,453
CAYMAN ISLANDS
Segment Information
Revenues									7,646	5,883	5,515
BRAZIL
Segment Information
Revenues									3,361	4,004	3,213
Long-Lived Assets	874				801				874	801
MEXICO
Segment Information
Revenues									3,185	3,709	2,934
CANADA
Segment Information
Revenues									2,400	2,272	1,818
UNITED KINGDOM
Segment Information
Revenues									2,219	2,231	1,848
Other Foreign [Member]
Segment Information
Revenues									16,443	18,364	$ 16,072
Long-Lived Assets	$ 2,974				$ 2,810				$ 2,974	$ 2,810