SEGMENT AND GEOGRAPHICAL INFORMATION - Long-lived Assets by Geography (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 165,353	$ 170,697
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	162,469	168,583
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 2,884	$ 2,114