Property and Equipment, net - Schedule of Property and Equipment Net (Detail) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,447	$ 2,328
Less: Accumulated depreciation and amortization	(1,699)	(1,631)
Property and equipment, net	748	697
Land
Property, Plant and Equipment [Line Items]
Property and equipment, gross	63	61
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	704	616
Capitalized software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	943	981
Furniture, fixtures & equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	509	484
Projects in process
Property, Plant and Equipment [Line Items]
Property and equipment, gross	134	92
Buses and support vehicles
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 94	$ 94