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

Information about Geographic Areas - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 15,618us-gaap_Revenues	$ 12,343us-gaap_Revenues	$ 10,881us-gaap_Revenues	$ 8,751us-gaap_Revenues	$ 10,120us-gaap_Revenues	$ 8,389us-gaap_Revenues	$ 7,218us-gaap_Revenues	$ 5,676us-gaap_Revenues	$ 47,593us-gaap_Revenues	$ 31,403us-gaap_Revenues	$ 22,973us-gaap_Revenues
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									$ 29,000	$ 19,300	$ 14,900