DERIVATIVES - AMOUNTS IN NET SALES AND OUTSTANDING COMMODITY DERIVATIVE CONTRACTS (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) item $ / bbl $ / MMBTU	Dec. 31, 2015 USD ($) item $ / bbl $ / MMBTU
Oil (in barrels) | Net sales
Outstanding commodity derivatives contracts not designated as hedging instruments
Gain (loss) on derivatives not designated as hedges | $	$ (5)	$ 28
Natural gas (in cubic feet) | Net sales
Outstanding commodity derivatives contracts not designated as hedging instruments
Gain (loss) on derivatives not designated as hedges | $	$ 1	$ (26)
Long position | Oil (in barrels)
Outstanding commodity derivatives contracts not designated as hedging instruments
Commodity contracts Volume (MMBOE OR Bcf) | item	67	83
Price (in USD per Bbl or mmbtu) | $ / bbl	53.86	45.25
Short position | Natural gas (in cubic feet)
Outstanding commodity derivatives contracts not designated as hedging instruments
Commodity contracts Volume (MMBOE OR Bcf) | item	12	5
Price (in USD per Bbl or mmbtu) | $ / MMBTU	3.19	2.72