Segment information - Segment Adjusted EBITDA to Net Income (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Net income (loss)	$ 14,509,000	$ 9,548,000	$ 22,307,000	$ 14,955,000
Depreciation and amortization	3,812,000	3,707,000	7,750,000	7,432,000
Interest expense	2,286,000	3,411,000	4,752,000	6,925,000
Interest income	(66,000)	(68,000)	(147,000)	(142,000)
Provision for income taxes	3,129,000	577,000	5,014,000	1,031,000
EBITDA	23,670,000	17,175,000	39,676,000	30,201,000
Loss (gain) on sale or disposition of assets and sublease	(47,000)	(105,000)	(225,000)	(248,000)
Loss on early extinguishment of debt	178,000		178,000	134,000
Equity-based compensation	74,000	321,000	332,000	701,000
Non-cash straight-line rent expense	270,000	371,000	417,000	710,000
Chairman executive compensation		750,000		1,500,000
Acquisition integration costs	45,000	222,000	63,000	222,000
Public offering related expenses		2,533,000		3,480,000
Adjusted EBITDA	24,190,000	21,267,000	40,441,000	36,700,000
Operating Segments | Real Estate Franchise Services
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Net income (loss)	14,188,000	8,431,000	22,558,000	14,214,000
Depreciation and amortization	3,742,000	3,610,000	7,610,000	7,221,000
Interest expense	2,283,000	3,410,000	4,745,000	6,922,000
Interest income	(66,000)	(68,000)	(147,000)	(142,000)
Provision for income taxes	3,073,000	577,000	5,056,000	1,031,000
EBITDA	23,220,000	15,960,000	39,822,000	29,246,000
Loss (gain) on sale or disposition of assets and sublease	(86,000)	(95,000)	(282,000)	(172,000)
Loss on early extinguishment of debt	178,000		178,000	134,000
Equity-based compensation	74,000	321,000	332,000	701,000
Non-cash straight-line rent expense	290,000	336,000	502,000	710,000
Chairman executive compensation		750,000		1,500,000
Acquisition integration costs	45,000	222,000	63,000	222,000
Public offering related expenses		2,533,000		3,480,000
Adjusted EBITDA	23,721,000	20,027,000	40,615,000	35,821,000
Operating Segments | Brokerage
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Net income (loss)	321,000	1,117,000	(251,000)	741,000
Depreciation and amortization	70,000	97,000	140,000	211,000
Interest expense	3,000	1,000	7,000	3,000
Interest income
Provision for income taxes	56,000		(42,000)
EBITDA	450,000	1,215,000	(146,000)	955,000
Loss (gain) on sale or disposition of assets and sublease	39,000	(10,000)	57,000	(76,000)
Non-cash straight-line rent expense	(20,000)	35,000	(85,000)
Adjusted EBITDA	$ 469,000	$ 1,240,000	$ (174,000)	$ 879,000