Property and Equipment, Net - Components of Property and Equipment, Net (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 742	$ 706
Less: accumulated depreciation	(551)	(512)
Total	191	194
Capitalized Website Development
Property Plant And Equipment [Line Items]
Property and equipment, gross	510	445
Total	103	91
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	37	46
Computer Equipment and Purchased Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	64	82
Furniture, Office Equipment and Other
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 17	$ 19