Summary of Significant Accounting Policies - Disaggregated revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Total revenue	$ 307,685	$ 325,671	$ 353,386
Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	22,687	29,510	31,063
Real Estate
Disaggregation of Revenue [Line Items]
Total revenue	214,093	227,182	249,272
Real Estate | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	195,264	201,388	221,887
Real Estate | Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	18,829	25,794	27,385
Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	78,983	83,861	90,319
Mortgage
Disaggregation of Revenue [Line Items]
Total revenue	14,609	13,993	12,388
Other
Disaggregation of Revenue [Line Items]
Total revenue		635	1,407
UNITED STATES | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	131,375	138,499	157,492
UNITED STATES | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	6,017	6,439	7,086
UNITED STATES | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	59,335	63,791	69,169
CANADA | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	40,693	40,805	42,289
CANADA | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	2,758	2,891	2,857
CANADA | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	18,521	19,039	19,993
Global | Global. | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	14,421	12,754	12,163
Global | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	$ 1,127	$ 1,031	$ 1,157