Segment Operating Results - Revenues Derived from Clients by Geographical Areas (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Net Revenues	$ 659,650	$ 447,995
United States [Member]
Segment Reporting Information [Line Items]
Net Revenues	460,648	365,400
Europe And Other [Member]
Segment Reporting Information [Line Items]
Net Revenues	198,614	80,021
Latin America [Member]
Segment Reporting Information [Line Items]
Net Revenues	$ 388	$ 2,574