Non-controlling Interest - Net income reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Minority Interest [Line Items]
Income (loss) before provision for income taxes attributable to RE/MAX Holdings, Inc.	$ (24,836)			$ 5,212			$ (17,208)	$ 14,836
Income (loss) before provision for income taxes: Non-controlling interest	(16,735)			3,683			(11,578)	10,067
Income (loss) before provision for income taxes	(41,571)			8,895			(28,786)	24,903
(Provision) benefit for income taxes attributable to RE/MAX Holdings, Inc.	(313)			(1,595)			(1,517)	(4,953)
(Provision) benefit for income taxes: Non-controlling interest	(479)			(462)			63	(1,631)
(Provision) benefit for income taxes	(792)			(2,057)			(1,454)	(6,584)
Net income (loss) attributable to RE/MAX Holdings, Inc.	(25,149)			3,617			(18,725)	9,883
Net income (loss): Non-controlling interest	(17,214)			3,221			(11,515)	8,436
Net income (loss)	$ (42,363)	$ 10,360	$ 1,763	6,838	$ 6,043	$ 5,438	$ (30,240)	18,319
RMCO, LLC
Minority Interest [Line Items]
Weighted average ownership percentage	100.00%						100.00%		100.00%
Net income (loss) attributable to RE/MAX Holdings, Inc.	$ (25,149)			$ 3,617			$ (18,725)	$ 9,883
RMCO, LLC | Weighted Average
Minority Interest [Line Items]
Weighted average ownership percentage attributable to RE/MAX Holdings, Inc.	59.80%			59.20%			59.80%	59.00%
Weighted average ownership percentage	100.00%			100.00%			100.00%	100.00%
RIHI | RMCO, LLC | Weighted Average
Minority Interest [Line Items]
Weighted average ownership percentage: Non-controlling interest	40.20%			40.80%			40.20%	41.00%