SEGMENT AND GEOGRAPHIC INFORMATION - Total Revenue by Major Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Revenues	$ 226,367	$ 197,523	$ 641,574	$ 577,643
United States
Segment Reporting Information [Line Items]
Revenues	178,290	150,867	493,559	433,865
Europe
Segment Reporting Information [Line Items]
Revenues	24,275	22,369	75,046	70,207
Rest of World
Segment Reporting Information [Line Items]
Revenues	$ 23,802	$ 24,287	$ 72,969	$ 73,571

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Name:	us-gaap_Revenues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration