Statements of Condensed Consolidated Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net income	$ 72,035	$ 122,255
Adjustments to reconcile net income to cash provided by operating activities:
Provision for losses on accounts receivable	196	2,717
Depreciation, depletion, and amortization	107,525	78,398
Unrealized losses on derivatives and inventory	5,484	896
Other income	(2,469)	(4,446)
Gain on dispositions	(1,110)	(22,785)
Equity in earnings of nonconsolidated investments	(2,212)	(2,358)
Equity award expense	8,256	3,998
Deferred income taxes	39,363	70,716
Changes in other assets and liabilities:
Dividend from Nora Gathering LLC	3,000	15,000
Inventory	55,628	67,245
Accounts receivable and unbilled revenues	36,251	14,573
Accounts payable	(55,969)	(41,108)
Other assets and liabilities	(43,854)	(62,587)
Net cash provided by operating activities	222,124	242,514
Cash flows from investing activities:
Capital expenditures	(269,587)	(263,428)
Proceeds from sale of available-for-sale investments		14,028
Proceeds from sale of assets	2,391	230,525
Net cash used in investing activities	(267,196)	(18,875)
Cash flows from financing activities:
Dividends paid	(32,938)	(32,886)
Decrease in short-term loans		(53,650)
Repayments and retirements of long-term debt	(9,532)
Proceeds and tax benefits from exercises under employee compensation plans	1,499	1,525
Net cash used in financing activities	(40,971)	(85,011)
Net (decrease) increase in cash and cash equivalents	(86,043)	138,628
Cash and cash equivalents at beginning of period	831,251
Cash and cash equivalents at end of period	745,208	138,628
Cash paid during the period for:
Interest, net of amount capitalized	13,044	10,791
Income taxes, net	$ 2,214	$ 29

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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).