CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities:
Net income	$ 115,722	$ 13,002	$ 58,026
Adjustments to reconcile net income to net cash provided from operating activities:
Gain from discontinued operations			(15,320)
(Gain) loss from equity method investments, net of distributions	(2,973)	5,670	16,871
Deferred income tax expense	34,000	13,832	34,920
Depletion, depreciation and amortization and impairment	500,150	480,782	379,902
Exploration dry hole costs	5,699	841	3,888
Abandonment and impairment of unproved properties	51,918	125,278	79,703
Derivative fair value loss (income)	61,825	(41,437)	(40,087)
Cash settlements on derivative financial instruments that do not qualify for hedge accounting	(31,256)	38,700	22,142
Allowance for bad debt	250	750	946
Amortization of deferred financing costs, loss on extinguishment of debt and other	23,866	23,165	25,458
Deferred and stock-based compensation	119,398	60,136	86,979
Gain on the sale of assets	(92,291)	(49,132)	(2,259)
Changes in working capital:
Accounts receivable	(21,212)	(38,017)	(37,789)
Inventory and other	3,785	(7,376)	865
Accounts payable	(13,555)	13,654	738
Accrued liabilities and other	(11,788)	7,251	(4,783)
Net cash provided from continuing operations	743,538	647,099	610,200
Net cash provided from discontinued operations			21,437
Net cash provided from operating activities	743,538	647,099	631,637
Investing activities:
Additions to natural gas and oil properties	(1,159,252)	(1,498,628)	(1,199,545)
Additions to field service assets	(5,925)	(4,762)	(11,607)
Acreage purchases	(132,145)	(191,065)	(226,500)
Equity method investments	3,799
Proceeds from disposal of assets	315,522	168,219	53,926
Purchases of marketable securities held by the deferred compensation plan	(36,136)	(60,406)	(25,388)
Proceeds from the sales of marketable securities held by the deferred compensation plan	30,701	58,084	20,410
Net cash used in investing activities from continuing operations	(983,436)	(1,528,558)	(1,388,704)
Net cash provided from discontinued operations			840,723
Net cash used in investing activities	(983,436)	(1,528,558)	(547,981)
Financing activities:
Borrowings on credit facilities	1,684,000	1,773,000	887,826
Repayments on credit facilities	(1,923,000)	(1,221,000)	(974,826)
Issuance of subordinated notes	750,000	600,000	500,000
Repayment of subordinated notes	(259,063)	(259,375)	(413,697)
Dividends paid	(26,129)	(25,981)	(25,756)
Debt issuance costs	(12,448)	(12,605)	(22,003)
Issuance of common stock	343	2,073	619
Change in cash overdrafts	5,610	(1,126)	(51,474)
Proceeds from the sales of common stock held by the deferred compensation plan	20,681	26,633	12,899
Net cash provided from (used in) financing activities	239,994	881,619	(86,412)
Increase (decrease) in cash and cash equivalents	96	160	(2,756)
Cash and cash equivalents at beginning of year	252	92	2,848
Cash and cash equivalents at end of year	$ 348	$ 252	$ 92