BASIS OF PRESENTATION - Schedule of Restricted Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Cash and cash equivalents	$ 250,452	$ 153,979
Restricted cash	25,862	0
Cash and cash equivalents and restricted cash	$ 276,314	$ 153,979	$ 3,697	$ 13,311