Revenue from Contract with Customer - Real Estate Services (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Total operating revenue	$ 26,337	$ 25,150	$ 20,952
Real estate
Disaggregation of Revenue [Line Items]
Total operating revenue	5,268	6,215	5,396
HomeServices | Real estate
Disaggregation of Revenue [Line Items]
Customer revenue	4,933	5,583	4,596
Other revenue	335	632	800
Total operating revenue	5,268	6,215	5,396
HomeServices | Brokerage
Disaggregation of Revenue [Line Items]
Customer revenue	4,867	5,498	4,520
HomeServices | Franchise
Disaggregation of Revenue [Line Items]
Customer revenue	$ 66	$ 85	$ 76