Revenue from Contracts with Customers - Changes in Deferred Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Movement in Deferred Revenue [Roll Forward]
Beginning balance	$ 365,274	$ 343,174
Acquired deferred revenue	6,872	6,880
Deferral of revenue	1,687,907	1,532,549
Recognition of deferred revenue	(1,681,297)	(1,515,892)
Currency translation	10,054	(1,437)
Ending balance	$ 388,810	$ 365,274