COMMODITY DERIVATIVE INSTRUMENTS - Schedule of Derivative Instruments (Details) bbl in Thousands	3 Months Ended
	Jun. 30, 2019 USD ($) $ / bbl bbl	Jun. 30, 2018 USD ($) $ / bbl bbl
Derivative [Line Items]
Derivative commodity asset (liability)	$ (108,557)	$ 695,941
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Derivative [Line Items]
Weighted Average Strike Price (in usd per barrel) | $ / bbl	54.40	48.78
Remaining Volume (Barrels) | bbl	150	60
Derivative commodity asset (liability)	$ (216,400)	$ (1,048,400)
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Derivative [Line Items]
Weighted Average Strike Price (in usd per barrel) | $ / bbl	79.08	68.69
Remaining Volume (Barrels) | bbl	150	60
Derivative commodity asset (liability)	$ 265,020	$ 1,097,124
Futures
Derivative [Line Items]
Weighted Average Strike Price (in usd per barrel) | $ / bbl	81.45	70.42
Remaining Volume (Barrels) | bbl	45	69
Derivative commodity asset (liability)	$ (157,177)	$ 394,317
Futures
Derivative [Line Items]
Weighted Average Strike Price (in usd per barrel) | $ / bbl		45.41
Remaining Volume (Barrels) | bbl		30
Derivative commodity asset (liability)		$ 252,900