DERIVATIVE INSTRUMENTS - Unobservable Inputs Narrative (Details) - Fair Value, Inputs, Level 3	12 Months Ended
Dec. 31, 2017
Minimum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Percentage of exit price premiums related to derivative contracts	6.00%
Maximum
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Percentage of exit price premiums related to derivative contracts	18.00%

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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