Supplemental Consolidated Financial Information - Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 6,446	$ 6,353
Accumulated depreciation	(5,203)	(5,115)
Property and equipment, net	1,243	1,238
Depreciation expense	441	442	$ 485
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 4,905	4,903
Computer equipment and software | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	1 year
Computer equipment and software | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Land and buildings, including building improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 829	792
Estimated useful lives	30 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 418	379
Estimated useful lives	5 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 141	138
Estimated useful lives	3 years
Construction in progress and other
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 153	$ 141