CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities:
Net (loss) income	$ (713,685)	$ 634,382	$ 115,722
Adjustments to reconcile net (loss) income to net cash provided from operating activities:
Loss (gain) from equity method investments, net of distributions		3,095	(2,973)
Deferred income tax (benefit) expense	(338,706)	396,502	34,000
Depletion, depreciation and amortization and impairment	1,171,329	579,056	500,150
Exploration dry hole and impairment costs	88	16,145	5,699
Abandonment and impairment of unproved properties	47,619	47,079	51,918
Derivative fair value (income) loss	(416,364)	(383,520)	61,825
Cash settlements on derivative financial instruments that do not qualify for hedge accounting	532,122	(42,634)	(31,256)
Allowance for bad debt	2,300	250	250
Amortization of deferred financing costs, loss on extinguishment of debt and other	29,383	24,694	23,866
Deferred and stock-based compensation	(20,411)	(4,295)	119,398
Loss (gain) on the sale of assets	406,856	(285,638)	(92,291)
Changes in working capital:
Accounts receivable	64,704	(5,329)	(21,212)
Inventory and other	(14,868)	(4,521)	3,785
Accounts payable	(26,197)	(1,023)	(13,555)
Accrued liabilities and other	(40,470)	(20,108)	(11,788)
Net cash provided from operating activities	683,700	954,135	743,538
Investing activities:
Additions to natural gas and oil properties	(1,030,644)	(1,200,419)	(1,159,252)
Additions to field service assets	(4,441)	(11,863)	(5,925)
Acreage purchases	(74,880)	(211,971)	(132,145)
Other	(75)	1,103	3,799
Proceeds from disposal of assets	890,901	180,508	315,522
Purchases of marketable securities held by the deferred compensation plan	(28,876)	(30,898)	(36,136)
Proceeds from the sales of marketable securities held by the deferred compensation plan	29,243	28,084	30,701
Net cash used in investing activities	(218,772)	(1,245,456)	(983,436)
Financing activities:
Borrowings on credit facilities	2,271,000	2,107,000	1,684,000
Repayments on credit facilities	(2,899,000)	(1,884,000)	(1,923,000)
Issuance of senior or senior subordinated notes	750,000	0	750,000
Repayment of senior subordinated notes	(516,875)	(312,000)	(259,063)
Dividends paid	(27,083)	(26,610)	(26,129)
Debt issuance costs	(14,156)	(8,866)	(12,448)
Issuance of common stock		396,562	343
Change in cash overdrafts	(37,089)	3,371	5,610
Proceeds from the sales of common stock held by the deferred compensation plan	8,298	15,964	20,681
Net cash (used in) provided from financing activities	(464,905)	291,421	239,994
Increase in cash and cash equivalents	23	100	96
Cash and cash equivalents at beginning of year	448	348	252
Cash and cash equivalents at end of year	$ 471	$ 448	$ 348