SEGMENT AND GEOGRAPHICAL INFORMATION - Long-lived Assets by Geographic Area (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 1,155,266	$ 1,144,721
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	1,100,550	1,086,379
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 54,716	$ 58,342