OTHER INFORMATION - Components of Other Current Assets (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Other Income and Expenses [Abstract]    
Inventory $ 21,940 $ 21,190
Deposits 1,720 1,445
Other receivables 4,906 9,302
Restricted cash 26,096 680
Other 4,052 6,582
Total other current assets $ 58,714 $ 39,199