REVENUES (Details 1) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
REVENUES
Unbilled trade receivables	$ 113,453	$ 68,494	$ 82,466	$ 39,223

Amount of unbilled receivables under long-term contracts that have not been billed and were not billable.

No definition available.

Name:	us-gaap_UnbilledReceivablesNotBillableAtBalanceSheetDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant