Summary of Significant Accounting Policies - Disaggregated revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation of Revenue [Line Items]
Total revenue	$ 88,943	$ 90,997	$ 272,119	$ 240,538
Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	7,390	7,052	24,841	21,130
Real Estate
Disaggregation of Revenue [Line Items]
Total revenue	62,655	64,623	193,168	172,068
Real Estate | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	56,189	58,628	171,266	154,223
Real Estate | Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	6,466	5,995	21,902	17,845
Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	22,736	23,269	68,496	59,456
Mortgage
Disaggregation of Revenue [Line Items]
Total revenue	3,194	2,620	9,337	7,353
Mortgage | Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	566	572	1,821	1,624
Other.
Disaggregation of Revenue [Line Items]
Total revenue	358	485	1,118	1,661
U.S. | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	39,975	42,922	121,862	113,081
U.S. | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	1,819	2,592	5,397	9,610
U.S. | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	17,186	18,471	52,386	51,012
Canada | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	10,764	8,889	32,673	17,243
Canada | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	723	1,258	2,141	5,827
Canada | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	5,201	4,541	15,202	7,702
Global | Global. | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	2,908	2,967	9,193	8,462
Global | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	$ 349	$ 257	$ 908	$ 742