BASIS OF PRESENTATION - Narrative (Details)	6 Months Ended
Jun. 30, 2018
Oil and Gas Properties
Discount rate for calculating present value of estimated future net revenues from proved reserves (as a percent)	10.00%
Minimum
Oil and Gas Delivery Commitments and Contracts [Line Items]
Oil and gas delivery commitments and contracts, period	1 month

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.

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