Summary of Significant Accounting Policies - Disaggregated revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Total revenue	$ 78,287	$ 85,401
Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	8,055	12,473
Real Estate
Disaggregation of Revenue [Line Items]
Total revenue	54,448	60,630
Real Estate | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	47,306	49,057
Real Estate | Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	7,142	11,573
Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	20,206	21,342
Mortgage
Disaggregation of Revenue [Line Items]
Total revenue	3,633	3,188
Mortgage | Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	913	659
Other.
Disaggregation of Revenue [Line Items]
Total revenue		241
U.S. | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	31,739	33,861
U.S. | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	1,468	1,476
U.S. | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	15,366	16,305
Canada | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	9,903	9,798
Canada | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	728	724
Canada | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	4,616	4,763
Global | Global. | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	3,468	3,198
Global | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	$ 224	$ 274