RELATED PARTIES (Details) - Schlumberger [Member] - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Related party purchases	$ 20.9	$ 28.4
Accounts Payable [Member]
Related Party Transaction [Line Items]
Related party purchases		$ 8.3

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration