Additional Financial Statement Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Other Revenues
Electricity Sales	$ 32	[1]	$ 73	[1]	$ 72	[1]
Refund of Deepwater Gulf of Mexico Royalties	0	[2]	0	[2]	86	[2]
Other	0		(1)		11
Total	32		72		169
Production Expense
Lease Operating Expense	397		376		372
Production and Ad Valorem Taxes	146		125		94
Transportation Expense	75		69		59
Total	618		570		525
Other Operating Expense, Net
Deepwater Gulf of Mexico Moratorium Expense	18	[3]	27	[3]	0	[3]
Electricity Generation Expense	26	[1]	39	[1]	18	[1]
Write-down of SemCrude L.P. Receivable	0	[4]	0	[4]	12	[4]
Loss on Involuntary Conversion	4	[5]	0	[5]	0	[5]
Other, Net	38		(2)		37
Total	86		64		67
Other Non-Operating (Income) Expense, Net
Deferred Compensation Expense	8	[6]	15	[6]	23	[6]
Interest Income	(8)	[7]	(7)	[7]	(13)	[7]
Other (Income) Expense, Net	2		(2)		2
Other Non-Operating (Income) Expense, Net	2		6		12
Accounts Receivable, Net [Abstract]
Commodity Sales	356		291
Joint Interest Billings	313		259
Other	123		33
Allowance for Doubtful Accounts	(9)	[8]	(27)	[8]
Total	783		556
Other Current Assets [Abstract]
Inventories, Current	78		112
Commodity Derivative Assets, Current	10		62
Deferred Income Taxes, Net, Current	41		9
Probable Insurance Claims	15	[9]	0	[9]
Prepaid Expenses and Other Assets, Current	36		18
Total	180		201
Other Noncurrent Assets [Abstract]
Equity Method Investments	329	[10]	285	[10]	303
Mutual Fund Investments	99		112
Commodity Derivative Assets, Noncurrent	37		0
Other Assets, Noncurrent	83		87
Total	548		484
Other Current Liabilities [Abstract]
Production and Ad Valorem Taxes	121		110
Commodity Derivative Liabilities, Current	76		24
Interest Rate Derivative Liability, Current	0		63
Income Taxes Payable	127		90
Asset Retirement Obligations, Current	33	[11]	45	[11]
Interest Payable	56		36
CONSOL Installment Payment	324	[12]	0	[12]
Current Portion of FPSO Lease Obligation	45		0
Other Liabilities, Current	143		127
Total	925		495
Other Noncurrent Liabilities [Abstract]
Deferred Compensation Liabilities, Noncurrent	222		229
Asset Retirement Obligations, Noncurrent	344	[11]	208	[11]
Accrued Benefit Costs, Noncurrent	88		76
Commodity Derivative Liabilities, Noncurrent	7		51
Other Liabilities, Noncurrent	91		66
Total	752		630
Interest in CONE Gathering LLC	50.00%
Cash Paid During the Year For [Abstract]
Interest, Net of Amount Capitalized	32		66		52
Income Taxes Paid, Net	288		173		227
Non-Cash Financing and Investing Activities [Abstract]
Increase in CONSOL Installment Loan, Net of Discount	639		0		0
Increase in FPSO Lease Obligation	66		266		29
Interest income on royalties refunds			$ 3		$ 11

[1] Amount represents electricity sales from the Machala power plant located in Machala, Ecuador. Electricity generation expense includes all operating and non-operating expenses associated with the plant, including DD&A and changes in the allowance for doubtful accounts. See Note 3. Acquisitions and Divestitures, Note 4. Asset Impairments, and Note 5. Allowance for Doubtful Accounts.

[2] The refund was attributable to royalties that we previously paid on crude oil and natural gas produced in the deepwater Gulf of Mexico from January 1, 2003 through July 31, 2009.

[3] 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.

[4] See Note 5. Allowance for Doubtful Accounts.

[5] 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.

[6] Amount represents increases in the fair value of shares of our common stock held in a rabbi trust. See Note 14. Benefit Plans.

[7] Interest income for 2010 and 2009 includes $3 million and $11 million, respectively, related to the refund of deepwater Gulf of Mexico royalties.

[8] 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 and Note 5. Allowance for Doubtful Accounts.

[9] Amount represents the costs incurred to date, net of insurance deductible and cash receipts for the Leviathan-2 appraisal well. See footnote (5) above.

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

[11] See Note 11. Asset Retirement Obligations

[12] See Note 3. Acquisitions and Divestitures and Note 12. Long-Term Debt.