SEGMENT AND GEOGRAPHIC INFORMATION - Summary of Net Revenues by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 79,674	$ 77,038	$ 74,704	$ 54,751	$ 90,601	$ 88,684	$ 79,185	$ 64,121	$ 286,166	$ 322,591	$ 357,249
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									199,565	259,080	303,195
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues									$ 86,601	$ 63,511	$ 54,054