Segment and Geographic Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2014 item	Mar. 31, 2013
Segment and Geographic Information
Number of operating segments	1
Number of reportable segments	1
Segment and Geographic Information
Revenue	$ 72,620	$ 49,438
Domestic
Segment and Geographic Information
Revenue	55,492	40,318
International
Segment and Geographic Information
Revenue	$ 17,128	$ 9,120

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

No definition available.

Name:	us-gaap_NumberOfOperatingSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration