NATURE OF BUSINESS, SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND OTHER - Other Current Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Other current assets
Net amounts due from joint interest partners	$ 70	$ 68
Derivative assets	39	168
Prepaid expenses	19	16
Other	2	3
Other current assets, net	130	255
Allowance For Doubtful Accounts
Other current assets
Net amounts due from joint interest partners	$ 22	$ 31