Property and Equipment, Net - Components of Property and Equipment, Net (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 767	$ 742
Less: accumulated depreciation	(567)	(551)
Total	200	191
Capitalized Website Development
Property Plant And Equipment [Line Items]
Property and equipment, gross	558	510
Total	115	103
Finance Lease Right-of-Use Asset
Property Plant And Equipment [Line Items]
Property and equipment, gross	114	114
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	24	37
Computer Equipment and Purchased Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	56	64
Furniture, Office Equipment and Other
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 15	$ 17