DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Schedule of Derivative Assets and Liabilities and Locations on Consolidated Balance Sheet (Details) - Recurring - Commodity Derivative Instruments - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative asset	$ 9	$ 55
Derivative liability	103	11
Current Assets: Other current assets
Derivatives, Fair Value [Line Items]
Derivative asset	2	55
Noncurrent Assets: Deferred charges and other
Derivatives, Fair Value [Line Items]
Derivative asset	7	0
Current Liabilities: Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability	0	11
Deferred Credits and Other Noncurrent Liabilities: Other
Derivatives, Fair Value [Line Items]
Derivative liability	$ 103	$ 0