Statements of Condensed Consolidated Cash Flows (USD $) In Thousands	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010
Cash flows from operating activities:
Net income	$ 388,923	$ 154,587
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation, depletion and amortization	247,627	195,644
Deferred income taxes	190,330	99,205
Gain on dispositions	(202,928)
Equity award expense	15,118	10,290
Other income	(27,948)	(8,551)
Provision for losses on accounts receivable	(176)	2,917
Unrealized (gains) losses on derivative financial instruments	(3,905)	(4,702)
Changes in operating assets and liabilities:
Accounts receivable and unbilled revenues	66,952	90,183
Inventory	467	15,589
Accounts payable	37,535	(57,402)
Derivative instruments at fair value, net	3,884	(9,294)
Federal income tax carryback refund		121,463
Other assets and liabilities	(2,544)	11,118
Net cash provided by operating activities	713,335	621,047
Cash flows from investing activities:
Additions to property, plant and equipment	(892,557)	(863,011)
Dividend from Nora Gathering, LLC	23,500
Proceeds from sale of available-for-sale securities	29,947
Proceeds from dispositions	619,999
Investment in available-for-sale-securities		(750)
Net cash used in investing activities	(219,111)	(863,761)
Cash flows from financing activities:
Dividends paid	(98,709)	(94,438)
Proceeds from issuance of common stock		537,239
Decrease in short-term loans	(53,650)	(5,000)
Repayments of long-term debt	(9,457)
Proceeds from exercises under employee compensation plans	2,504	2,280
Net cash (used in) provided by financing activities	(159,312)	440,081
Net increase in cash and cash equivalents	334,912	197,367
Cash and cash equivalents at beginning of period		0
Cash and cash equivalents at end of period	334,912	197,367
Cash paid (received) during the period for:
Interest, net of amount capitalized	76,934	80,703
Income taxes, net of refunds	$ 35,628	$ (124,124)

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Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits are not generally reported as cash and cash equivalents. Includes cash and cash equivalents associated with the entity's continuing operations. Excludes cash and cash equivalents associated with the disposal group (and discontinued operation).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 7

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

-Number 95

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-URI http://asc.fasb.org/extlink&oid=6506951

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-Paragraph 7, 26

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016