Business and Basis of Presentation - Narrative (Details) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	May 31, 2021 USD ($)	Jun. 30, 2021 USD ($) country enterprise	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) country enterprise segment	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of organizations Company serves | enterprise		14,000		14,000
Number of countries in which entity operates | country		100		100
Number of reportable segments | segment				3
Cash and cash equivalents, and restricted cash		$ 800,457	$ 356,633	$ 800,457	$ 356,633	$ 712,583	$ 280,836
Cash and cash equivalents		796,257		796,257		$ 712,583
Restricted cash		4,200		4,200
Proceeds from event cancellation insurance claims	$ 150,000
Gain on event cancellation insurance claims	$ 135,500	$ 135,545	$ 0	$ 135,545	$ 0