Segment Information and Geographic Data - Revenues by Geographical Region (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Total revenues	$ 228,385	$ 173,621	$ 630,961	$ 488,674
Americas [Member]
Segment Reporting Information [Line Items]
Total revenues	145,221	116,841	410,080	332,311
Europe [Member]
Segment Reporting Information [Line Items]
Total revenues	64,128	43,749	171,357	120,708
Asia Pacific [Member]
Segment Reporting Information [Line Items]
Total revenues	$ 19,036	$ 13,031	$ 49,524	$ 35,655
Revenue [Member] | Outside Of Americas [Member] | Geographic Concentration Risk [Member]
Segment Reporting Information [Line Items]
Percentage of revenues generated outside of the Americas	36.00%	33.00%	35.00%	32.00%