Gross Carrying Amount and Accumulated Amortization of Finite-lived Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 8,784	$ 804
Accumulated Amortization	(1,341)	(195)
Net Carrying Amount	7,443	609
Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,800
Accumulated Amortization	(462)
Net Carrying Amount	3,338
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,400
Accumulated Amortization	(291)
Net Carrying Amount	2,109
Domains/trademark/tradenames
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	320
Accumulated Amortization	(78)
Net Carrying Amount	242
Software license rights
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,654	804
Accumulated Amortization	(392)	(195)
Net Carrying Amount	1,262	609
Non-compete agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	610
Accumulated Amortization	(118)
Net Carrying Amount	$ 492