Information about Geographic Areas - Additional Information (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) Segment	Jun. 30, 2014 USD ($)
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of reportable segment | Segment			1
Total revenue	$ 13,066	$ 10,881	$ 24,659	$ 19,632
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 7,700	$ 6,900	$ 14,900	$ 12,200