Property And Equipment (Summary Of Property And Equipment) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 7,119	$ 8,259
Accumulated depreciation and amortization	(2,803)	(4,340)
Property and equipment, net	4,316	3,919
Computer Software, Purchased and Internally Developed [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	5,604	6,115
Computer Equipment, Furniture and Other Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	828	1,314
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	648	641
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	38	172
Land and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1	$ 17