Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Revenues and Long-lived Assets by Geographic Region are Based on the Physical Location of the Customers Being Served or the Assets (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 115,133	$ 95,284	$ 323,492	$ 253,674
Operating Segments [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	115,133	95,284	323,492	253,674
Long-lived assets	44,346		44,346		$ 39,008
Operating Segments [Member] | US [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	108,034	88,014	301,548	234,565
Long-lived assets	43,734		43,734		38,413
Operating Segments [Member] | International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	7,099	$ 7,270	21,944	$ 19,109
Long-lived assets	$ 612		$ 612		$ 595