DERIVATIVES AND HEDGE ACCOUNTING ACTIVITIES - Schedule of Volume of Derivative Activity (Details)	12 Months Ended
Dec. 31, 2017 Bcf
Fixed Price - Natural Gas - Current Derivative Contract
Derivative [Line Items]
Volume of derivative activity (bcf)	9.3
Fixed Price - Natural Gas - Non-current Derivative Contract
Derivative [Line Items]
Volume of derivative activity (bcf)	23.0

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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