Summary of Significant Accounting Policies - Disaggregated revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Total revenue	$ 78,453	$ 82,447	$ 156,740	$ 167,848
Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	5,407	6,361	13,462	18,834
Real Estate
Disaggregation of Revenue [Line Items]
Total revenue	54,749	57,559	109,197	118,189
Real Estate | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	50,322	52,295	97,628	101,352
Real Estate | Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	4,427	5,264	11,569	16,837
Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	20,027	21,077	40,233	42,419
Mortgage
Disaggregation of Revenue [Line Items]
Total revenue	3,677	3,616	7,310	6,804
Mortgage | Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	980	902	1,893	1,561
Other.
Disaggregation of Revenue [Line Items]
Total revenue		195		436
U.S. | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	33,977	36,075	65,716	69,936
U.S. | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	1,574	1,752	3,042	3,228
U.S. | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	14,964	16,100	30,330	32,405
Canada | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	10,603	10,541	20,506	20,339
Canada | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	659	723	1,387	1,447
Canada | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	4,804	4,721	9,420	9,484
Global | Global. | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	3,509	3,204	6,977	6,402
Global | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	$ 259	$ 256	$ 483	$ 530