Summary of Significant Accounting Policies - Disaggregated revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Total revenue	$ 78,478	$ 81,223	$ 235,218	$ 249,071
Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	4,698	5,825	18,160	24,659
Real Estate
Disaggregation of Revenue [Line Items]
Total revenue	54,639	56,563	163,836	174,752
Real Estate | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	51,010	51,751	148,638	153,103
Real Estate | Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	3,629	4,812	15,198	21,649
Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	20,098	20,853	60,331	63,272
Mortgage
Disaggregation of Revenue [Line Items]
Total revenue	3,741	3,640	11,051	10,444
Mortgage | Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	1,069	846	2,962	2,407
Other
Disaggregation of Revenue [Line Items]
Total revenue		167		603
UNITED STATES | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	34,378	35,504	100,094	105,440
UNITED STATES | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	1,549	1,668	4,591	4,896
UNITED STATES | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	14,889	15,638	45,219	48,043
CANADA | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	10,717	10,607	31,223	30,946
CANADA | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	707	721	2,094	2,168
CANADA | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	4,932	4,956	14,352	14,440
Global | Global. | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	3,659	3,251	10,636	9,653
Global | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	$ 277	$ 259	$ 760	$ 789