Business, Basis of Presentation and Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025
Disaggregation of Revenue [Line Items]
Subscription contract, minimum (in month)			1 month
Subscription contract, maximum (in years)			1 year
Subscription Revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 107	$ 86	$ 210	$ 171
Closing Fees
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	51	32	100	56
Appraisal Revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	11	10	22	19
Real Estate Brokerage
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	197	0	335	0
Real Estate Partner Revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	12	15	21	25
Real Estate Exchange Revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	18	0	33	0
License \| Zillow, Inc
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 50	$ 0	$ 92	$ 0
Upfront payment					$ 100