Intangible Assets, Net (Detail) - Intangible Assets, Net (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	$ 6,298	$ 3,430
Accumulated amortization	(2,704)	(1,593)
Net carrying amount	3,594	1,837
Trademarks [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	1,890	890
Accumulated amortization	(500)	(165)
Net carrying amount	1,390	725
Proprietary data and models [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	1,500	0
Accumulated amortization	(169)	0
Net carrying amount	1,331	0
Developed technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	728	665
Accumulated amortization	(319)	(128)
Net carrying amount	409	537
Covenant not to compete [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	480	80
Accumulated amortization	(155)	(22)
Net carrying amount	325	58
Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	250	250
Accumulated amortization	(111)	(49)
Net carrying amount	139	201
Other intangible assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	1,450	1,450
Accumulated amortization	(1,450)	(1,229)
Net carrying amount	0	221
Intangible assets in-progress [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Carrying amount	0	95
Accumulated amortization	0	0
Net carrying amount	$ 0	$ 95