Segment Information - Total Revenue from Unaffiliated Customers by Geographic Area, Based on Location of Customer (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 24,721	[1]	$ 19,944	[1]
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	15,414		13,015
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	5,390		4,435
Japan [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	1,453		1,303
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	2,282		1,093
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 182		$ 98

[1] Includes related party revenue (Note 10) $ 42 $ 880