Derivative Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2012

Derivative Financial Instruments [Abstract]

Outstanding contracts that are not designated for hedge accounting

				NYMEX Contract Price Per MMBtu
															Collars																Estimated
					Swaps		Additional Put								Floors								Ceilings								Fair Value
		Volume in			(Weighted							Weighted								Weighted								Weighted			Asset
	Period and Type of Contract		MMMBtus		Average)		Range						Average		Range						Average		Range						Average		(Liability)
																															(In millions)
	October 2012 – December 2012
	Price swap contracts		11,340		$	3.19					—			—					—			—					—			—	$	1
	Price swap contracts		(A)			2.72					—			—					—			—					—			—		(9)
	3-Way collar contracts		15,070			—	$	3.50	-	$	4.50		$	4.19	$	5.00	-	$	6.00		$	5.51	$	5.20	-	$	7.55		$	6.41		19
	January 2013 – December 2013
	Price swap contracts		54,750			4.08					—			—					—			—					—			—		13
	Price swap contracts		(A)			3.45					—			—					—			—					—			—		(15)
	3-Way collar contracts		39,530			—		3.50	-		4.50			4.04		5.00	-		6.00			5.44		6.00	-		7.55			6.48		42
	January 2014 – December 2014
	Price swap contracts		54,750			3.85					—			—					—			—					—			—		(17)
	Collar contracts		14,600			—					—			—					3.75			3.75		4.54	-		4.57			4.55		(1)
																															$	33
(A)	During the first quarter of 2012, natural gas spot market prices were below the puts we sold on our three-way collars for April through December 2012 and the full-year 2013, exposing us further to the softening natural gas spot market. As a result, during the first quarter of 2012 we entered into additional fixed-price swap contracts in the over-the-counter market that effectively prevented any further erosion in the value of our natural gas three-way collars. The new swap contracts added during the first quarter of 2012 were for the same volumes as our October through December 2012 and the full-year 2013 three-way collar contracts. The economics from the combination of these additional fixed-price swap contracts and our natural gas three-way collar contracts will result in effective average fixed prices of $4.04 and $4.85 per MMBtu for the fourth quarter of 2012 and the full-year 2013, respectively, as long as natural gas spot prices for the respective time periods settle below the puts we sold on our three-way collar contracts.

			NYMEX Contract Price Per Bbl
											Collars																Estimated
			Additional Put								Floors								Ceilings								Fair Value
	Volume in							Weighted								Weighted								Weighted			Asset
Period and Type of Contract		MBbls	Range						Average		Range						Average		Range						Average		(Liability)
																											(In millions)
October 2012 – December 2012
3-Way collar contracts		3,220	$	55.00	-	$	90.00		$	66.86	$	75.00	-	$	100.00		$	82.96	$	91.90	-	$	137.80		$	108.30	$	1
January 2013 – December 2013
3-Way collar contracts		12,115		80.00						80.00		95.00						95.00		106.50	-		130.40			118.05		30
January 2014 – December 2014
3-Way collar contracts		5,110		80.00						80.00		95.00						95.00		117.50	-		120.75			119.16		14
																											$	45

Natural gas basis contracts that are not designated for hedge accounting

	Rocky Mountains			Mid-Continent
	Volume in MMMbtus	Weighted- Average Differential		Volume in MMMbtus	Weighted- Average Differential		Estimated Fair Value Asset (Liability)
							(In millions)
October 2012 – December 2012	1,230	$	(0.91)	4,600	$	(0.55)	$	(3)

Derivative financial instruments recorded in balance sheet

				September 30,		December 31,
Type of Contract			Balance Sheet Location	2012		2011
				(In millions)
Derivatives not designated as hedging instruments:
	Natural gas contracts		Derivative assets – current	$	65	$	133
	Oil contracts		Derivative assets – current		24		1
	Basis contracts		Derivative assets – current		(1)		(5)
	Natural gas contracts		Derivative assets – noncurrent		1		61
	Oil contracts		Derivative assets – noncurrent		21		—
	Natural gas contracts		Derivative liabilities – current		(17)		—
	Oil contracts		Derivative liabilities – current		—		(45)
	Basis contracts		Derivative liabilities – current		(2)		(5)
	Natural gas contracts		Derivative liabilities – noncurrent		(16)		—
	Oil contracts		Derivative liabilities – noncurrent		—		(3)
		Total		$	75	$	137

Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Table Text Block]

			Location of Gain (Loss)	Three Months Ended September 30,				Nine Months Ended September 30,
Type of Contract			Recognized in Income	2012		2011		2012		2011
				(In millions)
Derivatives not designated as hedging instruments:
	Realized gain on natural gas contracts		Commodity derivative income (expense)	$	37	$	68	$	135	$	198
	Realized gain (loss) on oil contracts		Commodity derivative income (expense)		3		(5)		(4)		(37)
	Realized loss on basis contracts		Commodity derivative income (expense)		(3)		(2)		(8)		(5)
		Total realized gain			37		61		123		156
	Unrealized gain (loss) on natural gas contracts		Commodity derivative income (expense)		(79)		5		(162)		(68)
	Unrealized gain (loss) on oil contracts		Commodity derivative income (expense)		(59)		197		92		162
	Unrealized gain (loss) on basis contracts		Commodity derivative income (expense)		3		(1)		8		(1)
		Total unrealized gain (loss)			(135)		201		(62)		93
		Total		$	(98)	$	262	$	61	$	249