COMMODITY DERIVATIVE INSTRUMENTS -Schedule of Derivative Instruments (Details) bbl in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) $ / bbl bbl
Swap
Derivative [Line Items]
Weighted average trade price (in usd per barrel) | $ / bbl	48.78
Remaining volume (barrels) | bbl	60
Derivative liabilities, fair value | $	$ (1,048,400)
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Derivative [Line Items]
Weighted average trade price (in usd per barrel) | $ / bbl	68.69
Remaining volume (barrels) | bbl	60
Derivative commodity asset | $	$ 1,097,124
Futures
Derivative [Line Items]
Weighted average trade price (in usd per barrel) | $ / bbl	70.42
Remaining volume (barrels) | bbl	69
Derivative commodity asset | $	$ 394,317
Futures
Derivative [Line Items]
Weighted average trade price (in usd per barrel) | $ / bbl	45.41
Remaining volume (barrels) | bbl	30
Derivative commodity asset | $	$ 252,900