CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities:
Net (loss) income	$ (1,716,297,000)	$ (1,746,481,000)	$ 333,146,000
Adjustments to reconcile net (loss) income to net cash provided from operating activities:
Deferred income tax benefit	(506,438,000)	(30,489,000)	(251,043,000)
Depletion, depreciation and amortization and impairment of proved properties	1,644,477,000	658,081,000	688,671,000
Impairment of goodwill	0	1,641,197,000	0
Exploration dry hole and impairment costs	(11,000)	4,000	9,172,000
Abandonment and impairment of unproved properties	1,235,342,000	514,994,000	269,725,000
Derivative fair value (income) loss	(226,681,000)	51,192,000	(213,350,000)
Cash settlements on derivative financial instruments	188,384,000	(131,522,000)	13,117,000
Allowance for bad debt	4,341,000	(1,000,000)	1,550,000
Amortization of deferred financing costs and other	6,455,000	2,515,000	5,445,000
Deferred and stock-based compensation	24,891,000	29,757,000	30,706,000
Loss (gain) on the sale of assets	30,256,000	10,666,000	(23,716,000)
Gain on early extinguishment of debt	(5,415,000)	0	0
Changes in working capital:
Accounts receivable	214,196,000	(142,381,000)	(102,866,000)
Inventory and other	4,520,000	138,000	(2,979,000)
Accounts payable	(60,374,000)	(4,274,000)	45,912,000
Accrued liabilities and other	(155,803,000)	138,293,000	12,764,000
Net cash provided from operating activities	681,843,000	990,690,000	816,254,000
Investing activities:
Additions to natural gas and oil properties	(687,277,000)	(960,916,000)	(1,148,613,000)
Additions to field service assets	(1,162,000)	(1,477,000)	(5,710,000)
Acreage purchases	(59,986,000)	(60,603,000)	(58,213,000)
Proceeds from disposal of assets	784,937,000	324,549,000	72,468,000
Purchases of marketable securities held by the deferred compensation plan	(19,039,000)	(46,177,000)	(88,167,000)
Proceeds from the sales of marketable securities held by the deferred compensation plan	22,005,000	49,190,000	89,178,000
Net cash provided from (used in) investing activities	39,478,000	(695,434,000)	(1,139,057,000)
Financing activities:
Borrowings on credit facilities	2,311,000,000	2,070,000,000	2,041,000,000
Repayments on credit facilities	(2,777,000,000)	(2,338,000,000)	(1,712,000,000)
Repayment of senior or senior subordinated notes	(195,432,000)	0	(500,000)
Dividends paid	(20,070,000)	(19,940,000)	(19,839,000)
Treasury stock purchases	(6,908,000)	0	0
Debt issuance costs	(4,446,000)	(8,220,000)	(403,000)
Taxes paid for shares withheld	(3,384,000)	(3,183,000)	(6,983,000)
Change in cash overdrafts	(25,747,000)	(5,563,000)	17,180,000
Proceeds from the sales of common stock held by the deferred compensation plan	667,000	9,747,000	4,482,000
Net cash (used in) provided from financing activities	(721,320,000)	(295,159,000)	322,937,000
Increase in cash and cash equivalents	1,000	97,000	134,000
Cash and cash equivalents at beginning of year	545,000	448,000	314,000
Cash and cash equivalents at end of year	$ 546,000	$ 545,000	$ 448,000