Segment and Geographic Information - Summary of Revenues 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	$ 68,618	$ 66,155	$ 65,275	$ 60,304	$ 60,216	$ 54,948	$ 59,883	$ 51,696	$ 260,352	$ 226,743	$ 176,737
Domestic
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									176,187	161,716	128,997
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									$ 84,165	$ 65,027	$ 47,740