DEBT - Rattler's Credit Agreement (Details) - Rattler revolving credit facility - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 600
Long-term debt, gross	424	$ 0
Remaining borrowing capacity	$ 176
Minimum
Line of Credit Facility [Line Items]
Quarterly commitment fee percentage based on unused portion of borrowing base	0.25%
Minimum | Prime Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.25%
Minimum | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.25%
Maximum
Line of Credit Facility [Line Items]
Quarterly commitment fee percentage based on unused portion of borrowing base	0.375%
Maximum | Prime Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.25%
Maximum | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate	2.25%