Segment and Geographic Information - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) segment	Sep. 30, 2019 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment			1
Revenues	$ 6,435,637	$ 5,244,905	$ 18,351,614	$ 14,689,013
United States
Segment Reporting Information [Line Items]
Revenues	$ 2,800,000	$ 2,500,000	$ 8,000,000	$ 7,000,000