Segment Information - Revenue by Geographic Location (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 870,106	$ 784,535	$ 752,157	$ 640,799	$ 651,634	$ 578,165	$ 544,135	$ 714,718	$ 3,047,597	$ 2,488,652	$ 1,702,177
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									2,365,079	1,986,786	1,321,807
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									543,179	420,317	320,456
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									139,339	81,549	59,914
Total revenues outside of the United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									$ 682,518	$ 501,866	$ 380,370