Non-controlling Interest - Net income reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Minority Interest [Line Items]
Income before provision for income taxes - parent	$ 17,588	$ 34,163	$ 41,566
Income before provision for income taxes	29,708	58,296	66,721
Provision for income taxes attributable to RE/MAX Holdings, Inc.	(6,338)	(8,883)	(14,432)
Provision for income taxes	(9,162)	(10,982)	(16,419)
Net income attributable to RE/MAX Holdings, Inc.	11,250	25,280	27,134
Net income: Non-controlling interest	9,296	22,034	23,168
Net income	$ 20,546	$ 47,314	50,302
RMCO, LLC
Minority Interest [Line Items]
Parent economic interest in RMCO (as a percent)	59.40%	58.70%
Net income attributable to RE/MAX Holdings, Inc.	$ 11,250	$ 25,280	$ 27,134
RMCO, LLC | Weighted Average
Minority Interest [Line Items]
Parent economic interest in RMCO (as a percent)	59.10%	58.60%	58.60%
Total (as a percentage)	100.00%	100.00%	100.00%
RIHI
Minority Interest [Line Items]
Income before provision for income taxes: Non-controlling interest	$ 12,120	$ 24,133	$ 25,155
Provision for income taxes	(2,824)	(2,099)	(1,987)
Net income: Non-controlling interest	$ 9,296	$ 22,034	$ 23,168
RIHI | RMCO, LLC
Minority Interest [Line Items]
Weighted average ownership of non-controlling interest	40.60%	41.30%
RIHI | RMCO, LLC | Weighted Average
Minority Interest [Line Items]
Weighted average ownership of non-controlling interest	40.90%	41.40%	41.40%