RESTRICTED CASH - Schedule of Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash shown in the Consolidated Balance Sheets	$ 9,867	$ 8,080
Cash and cash equivalents	154,613	148,374
Total cash, cash equivalents and restricted cash shown in the Consolidated Statements of Cash Flows	164,480	$ 156,454	$ 177,688	$ 172,356
Restricted cash deposited with LKE intermediary
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash shown in the Consolidated Balance Sheets	9,317
Restricted cash held in escrow
Restricted Cash and Cash Equivalents Items [Line Items]
Total restricted cash shown in the Consolidated Balance Sheets	$ 550