Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities:
Net income (loss)	$ 881,914	$ 645,995	$ (42,267)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depletion, depreciation and amortization	607,405	499,856	564,149
Impairment of oil and gas properties	354,408		21,091
Exploration expenses, including dry holes	47,231	132,772	37,375
Hurricane activity, net		4,508	19,850
Deferred income taxes	188,579	259,763	(72,042)
(Gain) loss on disposition of assets, net	3,644	(19,074)	774
Accretion of discount on asset retirement obligations	8,256	7,945	8,050
Discontinued operations	(376,717)	77,158	38,386
Interest expense	31,483	30,472	27,996
Derivative related activity	(221,899)	(419,809)	75,633
Amortization of stock-based compensation	41,442	39,854	37,638
Amortization of deferred revenue	(44,951)	(90,216)	(147,905)
Other noncash items	(22,412)	25,102	30,623
Change in operating assets and liabilities
Accounts receivable, net	(47,331)	36,653	16,293
Income taxes receivable	29,406	(5,878)	36,030
Inventories	(137,401)	(26,281)	(46,708)
Prepaid expenses	(3,415)	(3,874)	(3,387)
Other current assets	1,957	(14,270)	87,642
Accounts payable	136,296	128,927	(65,862)
Interest payable	(1,768)	11,999	3,762
Income taxes payable	(7,623)	4,007	13,793
Other current liabilities	61,210	(40,586)	(97,855)
Net cash provided by operating activities	1,529,714	1,285,023	543,059
Cash flows from investing activities:
Proceeds from disposition of assets, net of cash sold	819,044	313,780	51,600
Investment in unconsolidated subsidiary	(89,620)	(72,864)
Additions to oil and gas properties	(1,926,965)	(1,011,442)	(437,240)
Additions to other assets and other property and equipment, net	(363,246)	(184,330)	(25,345)
Net cash used in investing activities	(1,560,787)	(954,856)	(410,985)
Cash flows from financing activities:
Borrowings under long-term debt	196,616	292,342	1,015,842
Principal payments on long-term debt	(294,883)	(475,252)	(1,175,703)
Proceeds from issuance of common stock, net of issuance	484,160
Proceeds from issuance of partnership common units, net of issuance costs	122,976		60,983
Contributions from noncontrolling interests		1,151	150
Distributions to noncontrolling interests	(26,702)	(26,837)	(20,012)
Borrowings (payments) of other liabilities	(901)	(21,329)	486
Exercise of long-term incentive plan stock options and employee stock purchases	3,696	7,375	8,506
Purchase of treasury stock	(40,355)	(14,039)	(21,921)
Excess tax (costs) benefits from share-based payment arrangements	31,087	(153)	1
Payment of financing fees	(8,741)	(145)	(12,005)
Dividends paid	(9,556)	(9,488)	(9,370)
Net cash provided by (used in) financing activities	457,397	(246,375)	(153,043)
Net increase (decrease) in cash and cash equivalents	426,324	83,792	(20,969)
Cash and cash equivalents, beginning of period	111,160	27,368	48,337
Cash and cash equivalents, end of period	$ 537,484	$ 111,160	$ 27,368