Summary of Significant Accounting Policies - Disaggregated revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Total revenue	$ 353,386	$ 329,701	$ 266,001
Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	31,063	27,801	26,279
Real Estate
Disaggregation of Revenue [Line Items]
Total revenue	249,272	235,124	190,792
Real Estate | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	221,887	211,618	169,966
Real Estate | Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	27,385	23,506	20,826
Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	90,319	82,391	64,402
Mortgage
Disaggregation of Revenue [Line Items]
Total revenue	12,388	10,051	6,610
Mortgage | Franchise sales and other revenue
Disaggregation of Revenue [Line Items]
Total revenue	2,271	2,160	1,256
Other.
Disaggregation of Revenue [Line Items]
Total revenue	1,407	2,135	4,197
U.S. | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	157,492	154,981	126,406
U.S. | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	7,086	11,392	13,345
U.S. | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	69,169	68,662	57,974
Canada | Company -Owned Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	42,289	27,234	12,659
Canada | Independent Regions | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	2,857	6,510	8,301
Canada | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	19,993	12,722	5,634
Global | Global. | Fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	12,163	11,501	9,255
Global | Marketing Funds
Disaggregation of Revenue [Line Items]
Total revenue	$ 1,157	$ 1,007	$ 794