Basis of Presentation (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013		Dec. 31, 2013
Production Expense
Lease Operating Expense	$ 133		$ 137		$ 432		$ 393
Production and Ad Valorem Taxes	44		51		146		137
Transportation and Gathering Expense	40		33		119		89
Total	217		221		697		619
Other Non-Operating (Income) Expense, Net
Deferred Compensation (Income) Expense	(12)	[1]	10	[1]	0	[1]	24	[1]
Other (Income) Expense, Net	(1)		(1)		1		(3)
Total	(13)		9		1		21
Accounts Receivable, Net
Commodity Sales	345				345				495
Joint Interest Billings	310				310				382
Other	101				101				81
Allowance for Doubtful Accounts	(16)				(16)				(11)
Total	740				740				947
Other Current Assets
Inventories, Materials and Supplies	95				95				96
Inventories, Crude Oil	28				28				25
Commodity Derivative Assets	79				79				1
Deferred Income Taxes, Net	5				5				62
Assets Held-for-Sale	98				98				292
Prepaid Expenses and Other Current Assets	56				56				71
Total	361				361				547
Other Noncurrent Assets
Equity Method Investments	290				290				437
Mutual Fund Investments	121				121				114
Commodity Derivative Assets	32				32				16
Other Assets	95				95				112
Total	538				538				679
Other Current Liabilities
Production and Ad Valorem Taxes	110				110				103
Commodity Derivative Liabilities	0				0				65
Income Taxes Payable	183				183				156
Asset Retirement Obligations	155				155				39
Interest Payable	56				56				63
Current Portion of Long Term Debt	0				0				200
Current Portion of Capital Lease	67				67				58
Liabilities Associated with Assets Held for Sale	12				12				111
Other	224				224				193
Total	807				807				988
Other Noncurrent Liabilities
Deferred Compensation Liabilities	264				264				253
Asset Retirement Obligations	543				543				547
Accrued Benefit Costs	108				108				155
Commodity Derivative Liabilities	0				0				10
Other	139				139				144
Total	$ 1,054				$ 1,054				$ 1,109

[1] Amounts represent increases (decreases) in the fair value of shares of our common stock held in a rabbi trust.