SEGMENT AND GEOGRAPHIC INFORMATION - Total Revenue by Major Geographic Area (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]
Revenues	$ 231,351	$ 205,547	$ 446,410	$ 402,199
United States
Segment Reporting Information [Line Items]
Revenues	178,806	157,166	342,187	307,185
Europe
Segment Reporting Information [Line Items]
Revenues	25,851	23,776	51,176	47,393
Rest of World
Segment Reporting Information [Line Items]
Revenues	$ 26,694	$ 24,605	$ 53,047	$ 47,621

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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

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