FAIR VALUE MEASUREMENT FAIR VALUE MEASUREMENT (Unobservable inputs) (Details) (USD $) In Millions, unless otherwise specified											12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Deferred Option Premiums and Accrued Interest [Member]	Dec. 31, 2013 Crude Oil Options [Member] Minimum [Member]	Dec. 31, 2013 Crude Oil Options [Member] Maximum [Member]	Dec. 31, 2013 Crude Oil Options [Member] Weighted Average [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member]		Dec. 31, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member]		Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Crude Oil Options [Member] Fair Value, Inputs, Level 3 [Member]		Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Crude Oil Options [Member] Fair Value, Inputs, Level 3 [Member] Sales [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Crude Oil Options [Member] Fair Value, Inputs, Level 3 [Member] Interest Expense [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Crude Oil Options [Member] Fair Value, Inputs, Level 3 [Member] Minimum [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Crude Oil Options [Member] Fair Value, Inputs, Level 3 [Member] Maximum [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Crude Oil Options [Member] Fair Value, Inputs, Level 3 [Member] Weighted Average [Member]	Dec. 31, 2013 Fair Value, Measurements, Recurring [Member] Warrant [Member] Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Assumptions, Implied Volatility Rate															17.00%	45.00%	23.00%
Deferred Premium Price				5.15	7.22	6.33
Derivative Liability	$ 320	$ 20	$ 444				$ 311	[1]	$ 0	[1],[2]	$ 0							$ 0
Derivative financial instruments assumed in the PXP acquisition											(83)							(10)
Net realized losses											(38)	[3]	37	1				0
Net unrealized (losses) gains included in earnings related to assets and liabilities still held at the end of the period											(230)	[4]	228	2				8	[5]
Settlement payments											42							0
Derivative Liability	$ 320	$ 20	$ 444				$ 311	[1]	$ 0	[1],[2]	$ (309)							$ (2)

[1] Recorded at fair value.

[2] rude oil options are net of $444 million for deferred premiums and accrued interest.

[3] Included net realized losses of $37 million recorded in revenues and $1 million of interest expense associated with the deferred premiums for the seven month period from June 1, 2013, to December 31, 2013.

[4] Included unrealized losses of $228 million recorded in revenues and $2 million of interest expense associated with the deferred premiums.

[5] Recorded in other (expense) income, net.