Additional Financial Statement Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Other Revenues [Abstract]
Other Revenues	$ 0		$ 32	[1]	$ 72	[1]
Production Expense
Lease Operating Expense	431		346		329
Production and Ad Valorem Taxes	151		146		125
Transportation Expense	91		66		61
Total	673		558		515
Other Operating Expense, Net
Deepwater Gulf of Mexico Moratorium Expense	0		18	[2]	27	[2]
Electricity Generation Expense	0		26	[1]	39	[1]
Other, Net	25		42		(2)
Total	25		86		64
Other Non-Operating (Income) Expense, Net
Deferred Compensation Expense	6	[3]	8	[3]	15	[3]
Interest Income	(1)		(8)		(7)	[4]
Other (Income) Expense, Net	1		9		(2)
Total	6		9		6
Interest income on royalties refunds					3
Accounts Receivable, Net
Commodity Sales	349		356
Joint Interest Billings	486		313
Other	139		123
Allowance for Doubtful Accounts	(10)		(9)
Total	964		783
Other Current Assets
Inventories, Current	90		78
Commodity Derivative Assets, Current	63		10
Deferred Income Taxes, Net, Current	106	[5]	41	[5]
Probable Insurance Claims	45	[6]	15	[6]
Assets Held for Sale	45	[7]	0	[7]
Prepaid Expenses and Other Assets, Current	71		36
Total	420		180
Other Noncurrent Assets
Equity Method Investments	367		329		285
Mutual Fund Investments	103		99
Commodity Derivative Assets, Noncurrent	21		37
Other Assets, Noncurrent	106		83
Total	597		548
Other Current Liabilities
Production and Ad Valorem Taxes	113		121
Commodity Derivative Liabilities, Current	7		76
Income Taxes Payable	203		127
Asset Retirement Obligations, Current	69		33
Interest Payable	55		56
CONSOL Installment Payment, Net	324	[8]	324	[8]
Current Portion of FPSO Lease Obligation	48		45
Liabilities Associated with Assets Held for Sale	12	[7]	0	[7]
Other Liabilities, Current	193		143
Total	1,024		925
Other Noncurrent Liabilities
Deferred Compensation Liabilities, Noncurrent	229		222
Asset Retirement Obligations, Noncurrent	333		344
Accrued Benefit Costs, Noncurrent	116	[9]	88	[9]
Commodity Derivative Liabilities, Noncurrent	3		7
Other Liabilities, Noncurrent	129		91
Total	$ 810		$ 752

[1] Other revenues consist primarily of electricity 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. In May 2011, we transferred our assets in Ecuador to the Ecuadorian government.

[2] Amounts relate to rig stand-by expense incurred due to the deepwater Gulf of Mexico drilling moratorium.

[3] Amounts represent increases in the fair value of shares of our common stock held in a rabbi trust.

[4] Interest income for 2010 includes $3 million related to the refund of deepwater Gulf of Mexico royalties.

[5] Increase from December 31, 2011 is due to reclassification of deferred income tax assets from long-term to short-term as certain foreign entities are estimated to begin utilizing net operating loss carryforwards in 2013.

[6] Amounts represent the costs incurred to date of the Leviathan-2 appraisal well and expected well abandonment costs in excess of the insurance deductible less insurance proceeds received to date. See Note 11. Asset Retirement Obligations.

[7] Assets held for sale consist primarily of North Sea oil and gas properties, and liabilities associated with assets held for sale consists primarily of asset retirement obligations.

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

[9] Amount includes liabilities accrued under our defined benefit pension plan, restoration plan, and other postretirement benefit plans. See Note 14. Stock-Based and Other Compensation Plans.