DERIVATIVES - GAINS AND LOSSES ON DERIVATIVES (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments	$ 233	$ 0	$ 0
Oil Collars and Calls | Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments	(107)	0	0
Marketing Derivatives | Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments	1,804	2,254	(138)
Interest Rate Swaps | Gain (Loss) on Interest Rate Swaps and Warrants, Net
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments	122	0	0
Interest Rate Swaps | Gain (Loss) on Interest Rate Swaps and Warrants, Net | WES
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments	30	0	0
Warrant | Gain (Loss) on Interest Rate Swaps and Warrants, Net
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) on derivative instruments	$ 81	$ 0	$ 0