Property and Equipment, Net (Detail) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 2,294	$ 2,109
Less: accumulated depreciation and amortization	(1,572)	(1,453)
Total property and equipment, net	722	656
Office and Computer Equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 322	400
Office and Computer Equipment | Minimum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	3 years
Office and Computer Equipment | Maximum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	10 years
Office Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 58	57
Office Furniture and Fixtures | Minimum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	3 years
Office Furniture and Fixtures | Maximum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	10 years
Internal-use Computer Software
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 1,649	1,417
Internal-use Computer Software | Minimum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	1 year
Internal-use Computer Software | Maximum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	10 years
Leasehold Improvements and Building
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 265	$ 235
Leasehold Improvements and Building | Minimum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	4 years
Leasehold Improvements and Building | Maximum
Property, Plant and Equipment [Line Items]
Property plant and equipment useful life	20 years