Basis of Presentation (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010		Dec. 31, 2010
Other Revenues [Abstract]
Electricity Sales	$ 0	[1]	$ 19	[1]	$ 32	[1]	$ 53	[1]
Other	0		(2)		1		(1)
Total	0		17		33		52
Production Expense [Abstract]
Lease Operating Expense	98		95		288		283
Production and Ad Valorem Taxes	38		29		108		96
Transportation Expense	17		17		53		51
Total	153		141		449		430
Other Operating (Income) Expense, Net [Abstract]
Deepwater Gulf of Mexico Moratorium Expense	(1)	[2]	0	[2]	18	[2]	27	[2]
Electricity Generation Expense	0	[1]	9	[1]	26	[1]	26	[1]
Loss on Involuntary Conversion	0	[3]	0	[3]	4	[3]	0	[3]
Other, Net	3		(5)		(3)		6
Total	2		4		45		59
Other Non-Operating (Income) Expense, Net [Abstract]
Deferred Compensation (Income) Expense	(18)	[4]	15	[4]	(15)	[4]	4	[4]
Interest Income	(2)		(1)		(7)		(4)
Other (Income) Expense, Net	4		(2)		6		(1)
Total	(16)		12		(16)		(1)
Accounts Receivable, Net [Abstract]
Commodity Sales	228				228				291
Joint Interest Billings	253				253				259
Other	73				73				33
Allowance for Doubtful Accounts	(8)	[5]			(8)	[5]			(27)	[5]
Total	546				546				556
Other Current Assets [Abstract]
Inventories, Current	120				120				112
Commodity Derivative Assets, Current	87				87				62
Deferred Income Taxes, Net, Current	15	[6]			15	[6]			8	[6]
Probable Insurance Claims	25	[6]			25	[6]			0	[6]
Prepaid Expenses and Other Assets, Current	32				32				19
Total	279				279				201
Other Noncurrent Assets [Abstract]
Equity Method Investments	339	[7]			339	[7]			285	[7]
Mutual Fund Investments	101				101				112
Commodity Derivative Assets, Noncurrent	44				44				0
Other Assets, Noncurrent	64				64				87
Total	548				548				484
Other Current Liabilities [Abstract]
Production and Ad Valorem Taxes	128				128				110
Commodity Derivative Liabilities, Current	6				6				24
Interest Rate Derivative Liability, Current	0				0				63
Income Taxes Payable	143				143				90
Asset Retirement Obligations, Current	45				45				45
Interest Payable	18				18				36
CONSOL Installment Payment	322	[8]			322	[8]			0	[8]
Current Portion of FPSO Lease Obligation	33				33				0
Other	131				131				127
Total	826				826				495
Other Noncurrent Liabilities [Abstract]
Deferred Compensation Liabilities, Noncurrent	210				210				229
Asset Retirement Obligations, Noncurrent	215				215				208
Accrued Benefit Costs, Noncurrent	63				63				76
Commodity Derivative Liabilities, Noncurrent	0				0				51
Other	63				63				66
Total	$ 551				$ 551				$ 630
Interest in CONE Gathering LLC	50.00%				50.00%

[1] Electricity sales include sales from the Machala power plant located in Machala, Ecuador, through May 2011. Electricity generation expense includes all operating and non-operating expenses associated with the plant, including depreciation and changes in the allowance for doubtful accounts. See Note 3. Acquisitions and Divestitures.

[2] Amounts relate to rig stand-by expense incurred prior to receiving a permit to resume drilling activities in the deepwater Gulf of Mexico in 2011 and costs to terminate a deepwater Gulf of Mexico drilling rig contract due to the deepwater Gulf of Mexico drilling moratorium in 2010.

[3] The loss on involuntary conversion represents our insurance deductible related to the Leviathan-2 appraisal well control incident. We suspended operations on the Leviathan-2 well, offshore Israel, in May 2011 when we identified water flowing to the sea floor from the wellbore. The incident was a covered event under our well control insurance. At this time, we expect to recover most of the costs from insurance, subject to a deductible. The final amount to be recovered will be based on the cost to drill the Leviathan-3 replacement well down to the same depth at which the incident occurred, possible remediation activities and/or abandonment activities at the Leviathan-2 well, which have not yet been determined, and other factors. See footnote (2) below.

[4] Amount represents increases (decreases) in the fair value of shares of our common stock held in a rabbi trust.

[5] The decrease in the allowance for doubtful accounts from December 31, 2010 is due primarily to the transfer of assets to the Ecuadorian government. See Note 3. Acquisitions and Divestitures.

[6] Amount represents the costs incurred to date of the Leviathan-2 appraisal well in excess of the insurance deductible. See footnote (3) above.

[7] The increase in equity method investments from December 31, 2010 is due to our acquisition of a 50% interest in CONE Gathering LLC. See Note 3. Acquisitions and Divestitures.

[8] See Note 3. Acquisitions and Divestitures and Note 5. Debt.