Goodwill, Customer Relationships and Other Intangible Assets - Goodwill, Customer Relationships, and Other Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023
Goodwill [Line Items]
Goodwill	$ 1,964		$ 1,964
Indefinite-lived intangible assets	9		9
Finite-lived intangible assets, net	4,958
Total other intangible assets, net	4,967		5,470
Customer Relationships
Goodwill [Line Items]
Finite-lived intangible assets, net	3,346		3,811
Accumulated amortization	4,361		4,248
Capitalized Software
Goodwill [Line Items]
Finite-lived intangible assets, net	1,536		1,564
Accumulated amortization	4,112		4,045
Trade Names, Patents and Other
Goodwill [Line Items]
Finite-lived intangible assets, net	76		86
Accumulated amortization	$ 82		$ 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