Property And Equipment (Summary Of Property And Equipment) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 6,479	$ 5,548
Accumulated depreciation and amortization	(3,346)	(2,813)
Property and equipment, net	3,133	2,735
Computer Software, Purchased and Internally Developed [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	4,314	3,532
Computer Equipment, Furniture and Other Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,264	1,266
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	715	563
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	169	169
Land and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 17	$ 18

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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