Goodwill, Customer Relationships and Other Intangible Assets - Goodwill, Customer Relationships, and Other Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Goodwill [Line Items]
Goodwill	$ 1,964	$ 1,964
Indefinite-lived intangible assets	9	9
Total other intangible assets, net	5,290	5,470
Customer Relationships
Goodwill [Line Items]
Finite-lived intangible assets, net	3,656	3,811
Accumulated amortization	4,047	4,248
Capitalized Software
Goodwill [Line Items]
Finite-lived intangible assets, net	1,542	1,564
Accumulated amortization	3,981	4,045
Trade Names, Patents and Other
Goodwill [Line Items]
Finite-lived intangible assets, net	83	86
Accumulated amortization	75	$ 72
Fully Amortized and Retired Customer Relationships
Goodwill [Line Items]
Gross carrying value	352
Fully Amortized and Retired Capitalized Software
Goodwill [Line Items]
Gross carrying value	$ 153