SEGMENT AND GEOGRAPHICAL INFORMATION - Revenue by Geographic Area (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 4,713,500	$ 3,298,177	$ 2,214,253
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	4,472,473	3,138,859	2,120,088
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 241,027	$ 159,318	$ 94,165