Information about Geographic Areas - Classification of Revenue by Geography (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 36,931	$ 30,604	$ 30,345	$ 27,688	$ 30,032	$ 28,616	$ 24,999	$ 23,085	$ 125,568	$ 106,732	$ 114,905
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									86,139	74,137	86,099
Europe & Middle East
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									30,289	25,715	21,791
Asia Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									$ 9,140	$ 6,880	$ 7,015