Revenue from Contracts with Customers - Changes in Deferred Revenue (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Movement in Deferred Revenue [Roll Forward]
Beginning balance	$ 365,274	$ 343,174
Acquired deferred revenue	1,405	3,266
Deferral of revenue	1,025,057	991,524
Recognition of revenue	(1,057,611)	(1,029,664)
Currency translation	4,307	(4,985)
Ending balance	$ 338,432	$ 303,315