Segment information - Reportable Segments Revenue and Adjusted EBITDA (Detail) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Sales Information [Line Items]
Continuing franchise fees									$ 64,465,000		$ 56,350,000		$ 57,200,000
Annual dues									29,524,000		28,909,000		28,922,000
Broker fees									24,811,000		19,579,000		16,764,000
Franchise sales and other franchise revenue									23,574,000		22,629,000		19,354,000
Brokerage revenue									16,488,000		16,210,000		16,062,000
Total revenue	40,234,000	40,312,000	39,241,000	39,075,000	35,080,000	38,429,000	35,167,000	35,001,000	158,862,000		143,677,000		138,302,000
Total segment reporting adjusted EBITDA									77,286,000		66,744,000		59,281,000
Real Estate Franchise Services
Sales Information [Line Items]
Total segment reporting adjusted EBITDA									78,024,000		66,776,000		60,590,000
Brokerage And Other
Sales Information [Line Items]
Total segment reporting adjusted EBITDA									(738,000)		(32,000)		(1,309,000)
Operating Segments
Sales Information [Line Items]
Total revenue									158,862,000	[1]	143,677,000	[1]	138,302,000	[1]
Operating Segments | Real Estate Franchise Services
Sales Information [Line Items]
Continuing franchise fees									65,728,000	[1]	57,599,000	[1]	58,487,000	[1]
Annual dues									29,527,000	[1]	28,913,000	[1]	28,922,000	[1]
Broker fees									25,078,000	[1]	19,797,000	[1]	16,923,000	[1]
Franchise sales and other franchise revenue									23,577,000	[1]	22,636,000	[1]	19,364,000	[1]
Brokerage revenue										[1]		[1]		[1]
Total revenue									143,910,000	[1]	128,945,000	[1]	123,696,000	[1]
Operating Segments | Brokerage And Other
Sales Information [Line Items]
Continuing franchise fees									(1,263,000)	[1]	(1,249,000)	[1]	(1,287,000)	[1]
Annual dues									(3,000)	[1]	(4,000)	[1]
Broker fees									(267,000)	[1]	(218,000)	[1]	(159,000)	[1]
Franchise sales and other franchise revenue									(3,000)	[1]	(7,000)	[1]	(10,000)	[1]
Brokerage revenue									16,488,000	[1]	16,210,000	[1]	16,062,000	[1]
Total revenue									$ 14,952,000	[1]	$ 14,732,000	[1]	$ 14,606,000	[1]

[1] Transactions between the Real Estate Franchise Services and the Brokerage and Other reportable segments are eliminated in consolidation. Revenues for the Real Estate Franchise Services segment include intercompany amounts paid from the Company’s Brokerage Services business of $1,536,000, $1,478,000 and $1,456,000 for the years ended December 31, 2013, 2012 and 2011, respectively. Such amounts are eliminated through the Brokerage and Other reportable segment.