RESTRICTED CASH - Schedule of Restricted Cash (Details) - USD ($) $ in Thousands		Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash shown in the Consolidated Balance Sheets		$ 84,903	$ 59,703
Cash and cash equivalents		92,785	112,653
Total cash, cash equivalents and restricted cash shown in the Consolidated Statements of Cash Flows	[1]	177,688	$ 172,356	$ 330,633	$ 157,617
Deposited with intermediary
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash shown in the Consolidated Balance Sheets		84,353
Held in escrow
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash shown in the Consolidated Balance Sheets		$ 550

[1] Due to the adoption of ASU No. 2016-18, restricted cash is now included with cash and cash equivalents when reconciling the beginning-of-year and end-of-period total amounts shown and therefore changes in restricted cash are no longer reported as investing activities. Prior period amounts have been restated to conform to current period presentation. For additional information and a reconciliation of cash, see