Segment Information - Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information
Total revenue	$ 325,671	$ 353,386	$ 329,701
Real Estate
Segment Reporting Information
Total revenue	227,182	249,272	235,124
Mortgage
Segment Reporting Information
Total revenue	13,993	12,388	10,051
Marketing Funds fees
Segment Reporting Information
Total revenue	83,861	90,319	82,391
Other.
Segment Reporting Information
Total revenue	635	1,407	2,135
Continuing franchise fees
Segment Reporting Information
Total revenue	127,384	133,389	118,504
Continuing franchise fees | Real Estate
Segment Reporting Information
Total revenue	116,472	123,272	110,613
Continuing franchise fees | Mortgage
Segment Reporting Information
Total revenue	10,912	10,117	7,891
Annual dues
Segment Reporting Information
Total revenue	33,904	35,676	35,549
Annual dues | Real Estate
Segment Reporting Information
Total revenue	33,904	35,676	35,549
Broker fees
Segment Reporting Information
Total revenue	51,012	62,939	65,456
Broker fees | Real Estate
Segment Reporting Information
Total revenue	51,012	62,939	65,456
Franchise sales and other revenue
Segment Reporting Information
Total revenue	29,510	31,063	27,801
Franchise sales and other revenue | Real Estate
Segment Reporting Information
Total revenue	25,794	27,385	23,506
Franchise sales and other revenue | Mortgage
Segment Reporting Information
Total revenue	$ 3,081	$ 2,271	$ 2,160