Segment and Geographic Information - Narrative (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) segment	Jun. 30, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment			1
Revenues	$ 7,341,777	$ 6,148,286	$ 14,505,059	$ 11,915,977
United States
Segment Reporting Information [Line Items]
Revenues	$ 3,000,000	$ 2,700,000	$ 6,000,000	$ 5,200,000