Equity Method Investments - Schedule of Equity Method Investment (Details) - USD ($) $ in Millions	Jun. 30, 2026	Apr. 30, 2026	Dec. 31, 2025
Schedule of Equity Method Investments [Line Items]
Total equity method investments	$ 217		$ 17
Mortgage joint ventures \| Integrated Services
Schedule of Equity Method Investments [Line Items]
Total equity method investments	$ 83		14
Equity method investment, ownership percentage	49.90%
Title insurance underwriter joint venture \| Integrated Services
Schedule of Equity Method Investments [Line Items]
Total equity method investments	$ 68		0
Equity method investment, ownership percentage	22.00%
Brokerage equity method investments \| Brokerage
Schedule of Equity Method Investments [Line Items]
Total equity method investments	$ 57		0
Other equity method investments \| Integrated Services
Schedule of Equity Method Investments [Line Items]
Total equity method investments	$ 9		$ 3
Sotheby \| Brokerage
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	50.00%
Parent
Schedule of Equity Method Investments [Line Items]
Total equity method investments	$ 23
Equity method investment, ownership percentage		51.00%
Parent \| Brokerage
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	51.00%