Summary of Significant Accounting Policies - Disaggregated revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Total revenue	$ 325,671	$ 353,386	$ 329,701
Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	29,510	31,063	27,801
Real Estate
Disaggregation of Revenue [Line Items]
Total revenue	227,182	249,272	235,124
Real Estate | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	201,388	221,887	211,618
Real Estate | Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	25,794	27,385	23,506
Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	83,861	90,319	82,391
Mortgage
Disaggregation of Revenue [Line Items]
Total revenue	13,993	12,388	10,051
Mortgage | Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	3,081	2,271	2,160
Other.
Disaggregation of Revenue [Line Items]
Total revenue	635	1,407	2,135
U.S. | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	138,499	157,492	154,981
U.S. | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	6,439	7,086	11,392
U.S. | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	63,791	69,169	68,662
Canada | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	40,805	42,289	27,234
Canada | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	2,891	2,857	6,510
Canada | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	19,039	19,993	12,722
Global | Global. | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	12,754	12,163	11,501
Global | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	$ 1,031	$ 1,157	$ 1,007