Consolidated Statements of Cash Flows (unaudited) (USD $) In Millions	9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010
Cash Flows From Operating Activities
Net Income	$ 749		$ 673
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Depreciation, Depletion and Amortization	681		662
Asset Impairments	139		100
Dry Hole Cost	57		57
Deferred Income Taxes	147		109
Dividends (Income) from Equity Method Investees, Net	23		6
Unrealized Gain on Commodity Derivative Instruments	(140)		(215)
Gain on Divestitures	(26)	[1]	(114)	[1]
Other Adjustments for Noncash Items Included in Income	52		40
Changes in Operating Assets and Liabilities
(Increase) in Accounts Receivable	(7)		(63)
(Increase) Decrease in Other Current Assets	(17)		18
Increase in Accounts Payable	131		214
Increase in Current Income Taxes Payable	52		20
(Decrease) in Other Current Liabilities	(25)		(17)
Other Operating Assets and Liabilities, Net	(31)		(38)
Net Cash Provided by Operating Activities	1,785		1,452
Cash Flows From Investing Activities
Additions to Property, Plant and Equipment	(1,868)		(1,326)
Marcellus Shale Asset Acquisition	(519)		0
Central DJ Basin Asset Acquisition	0		(458)
Additions to Equity Method Investments	(73)		0
Proceeds from Divestitures	77		552
Net Cash Used in Investing Activities	(2,383)		(1,232)
Cash Flows From Financing Activities
Exercise of Stock Options	32		35
Excess Tax Benefits from Stock-Based Awards	11		19
Dividends Paid, Common Stock	(104)		(95)
Purchase of Treasury Stock	(16)		(12)
Proceeds from Credit Facilities	520		760
Repayment of Credit Facilities	(470)		(792)
Proceeds from Issuance of Senior Long-Term Debt, Net	836		0
Settlement of Interest Rate Derivative Instrument	(40)		0
Net Cash Provided By (Used In) Financing Activities	769		(85)
Increase in Cash and Cash Equivalents	171		135
Cash and Cash Equivalents at Beginning of Period	1,081		1,014
Cash and Cash Equivalents at End of Period	$ 1,252		$ 1,149

[1] See Note 3. Acquisitions and Divestitures.