THE SPIN-OFF, SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND OTHER (Details2) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
PROPERTY, PLANT AND EQUIPMENT
Maximum time period after which costs of exploratory wells are charged to expense if determination of proved reserves has not been made			12 months	12 months	12 months
Net capitalized costs attributable to unproved properties	$ 300		$ 300
Capitalized exploratory well costs for the years ended December 31:
Balance - Beginning of Year			4	$ 18	$ 18
Additions to capitalized exploratory well costs pending the determination of proved reserves			16	3	46
Reclassifications to property, plant and equipment based on the determination of proved reserves			(5)	(8)	(31)
Capitalized exploratory well costs charged to expense			(9)	(9)	(15)
Balance - End of Year	6	$ 4	6	4	18
ASSET RETIREMENT OBLIGATIONS
Asset retirement obligation, included in other long-term liabilities	343	397	343	397
Asset Retirement Obligations Rollforward
Beginning balance			415	415
Liabilities incurred - capitalized to PP&E			7	19
Liabilities settled and paid			(18)	(29)
Accretion expense			20	22
Acquisitions, dispositions and other - changes in PP&E				22
Revisions to estimated cash flows - changes in PP&E			(67)	(34)
Ending balance	357	415	$ 357	415	415
Share-based Compensation
Percentage of PSU performance target based on specified VCI results			50.00%
Percentage of PSU performance target based on TSR relative to selected peer group			50.00%
Accrued liabilities
Accrued employee-related costs	105	95	$ 105	95
Interest payable	40	70	40	70
Greenhouse gas emission liabilities		65		65
Supplemental Cash Flow Information
United States federal and state income taxes paid				165	318
Taxes on other than income			154	183	185
Interest Paid			359	3	$ 0
Transfer of trade receivables				400
Other Assets
Other assets
Net deferred tax assets, other	199		199
Other current assets
Other current assets
Amounts due from joint interest partners	40	120	40	120
Greenhouse gas emission assets		65		65
Deferred tax assets, net	59	61	59	$ 61
Derivatives from commodities contracts	87		$ 87
Major customers | Conoco Phillips / Phillips 66 and Tesoro Refining & Marketing Company LLC Combined Member
Major Customers
Concentration Risk, Percentage				45.00%	42.00%
Major customers | Conoco Phillips / Phillips 66, Tesoro Refining & Marketing Company LLC and Valero Marketing & Supply Company Combined
Major Customers
Concentration Risk, Percentage			61.00%
Minimum | Major customers | Conoco Phillips / Phillips 66 and Tesoro Refining & Marketing Company LLC Combined Member
Major Customers
Concentration Risk, Percentage				10.00%	10.00%
Minimum | Major customers | Conoco Phillips / Phillips 66, Tesoro Refining & Marketing Company LLC and Valero Marketing & Supply Company Combined
Major Customers
Concentration Risk, Percentage			10.00%
Gas Plant And Power Plant Assets Member | Minimum
PROPERTY, PLANT AND EQUIPMENT
Expected useful lives			2 years
Gas Plant And Power Plant Assets Member | Maximum
PROPERTY, PLANT AND EQUIPMENT
Expected useful lives			30 years
Other Non- Producing Property and Equipment | Minimum
PROPERTY, PLANT AND EQUIPMENT
Expected useful lives			2 years
Other Non- Producing Property and Equipment | Maximum
PROPERTY, PLANT AND EQUIPMENT
Expected useful lives			20 years
Proved and unproved properties
Asset Impairments
Asset impairment charges	4,900	3,400	$ 4,900	$ 3,400
Unproved properties
Asset Impairments
Asset impairment charges	$ 100	$ 650	$ 100	$ 650