COMMODITY DERIVATIVE INSTRUMENTS - Schedule of Derivative Instruments (Details) bbl in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) $ / bbl bbl	Dec. 31, 2018 USD ($) $ / bbl bbl
Swap
Derivative [Line Items]
Weighted average trade price (in usd per barrel) | $ / bbl	40.88	48.78
Remaining volume (barrels) | bbl	130	60
Derivative assets, fair value	$ 539,800
Derivative liabilities, fair value		$ (1,048,400)
Swap
Derivative [Line Items]
Weighted average trade price (in usd per barrel) | $ / bbl	81.19	68.69
Remaining volume (barrels) | bbl	130	60
Derivative assets, fair value		$ 1,097,124
Derivative liabilities, fair value	$ (673,428)
Futures
Derivative [Line Items]
Weighted average trade price (in usd per barrel) | $ / bbl	84.83	70.42
Remaining volume (barrels) | bbl	105	69
Derivative assets, fair value		$ 394,317
Derivative liabilities, fair value	$ (242,222)
Futures
Derivative [Line Items]
Weighted average trade price (in usd per barrel) | $ / bbl		45.41
Remaining volume (barrels) | bbl		30
Derivative assets, fair value		$ 252,900