Summary of Significant Accounting Policies - Disaggregated revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Total revenue	$ 82,447	$ 92,172	$ 167,848	$ 183,176
Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	6,361	6,802	18,834	17,451
Real Estate
Disaggregation of Revenue [Line Items]
Total revenue	57,559	65,776	118,189	130,513
Real Estate | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	52,295	59,952	101,352	115,077
Real Estate | Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	5,264	5,824	16,837	15,436
Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	21,077	22,909	42,419	45,760
Mortgage
Disaggregation of Revenue [Line Items]
Total revenue	3,616	3,115	6,804	6,143
Mortgage | Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	902	606	1,561	1,255
Other.
Disaggregation of Revenue [Line Items]
Total revenue	195	372	436	760
U.S. | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	36,075	42,733	69,936	81,887
U.S. | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	1,752	1,877	3,228	3,578
U.S. | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	16,100	17,641	32,405	35,200
Canada | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	10,541	11,434	20,339	21,909
Canada | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	723	715	1,447	1,418
Canada | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	4,721	4,988	9,484	10,001
Global | Global. | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	3,204	3,193	6,402	6,285
Global | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	$ 256	$ 280	$ 530	$ 559