CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating activities:
Net income (loss)	$ 333,146,000	$ (521,388,000)	$ (713,685,000)
Adjustments to reconcile net income (loss) to net cash provided from operating activities:
Deferred income tax benefit	(251,043,000)	(280,848,000)	(338,706,000)
Depletion, depreciation and amortization and impairment	688,671,000	567,142,000	1,171,329,000
Exploration dry hole and impairment costs	9,172,000	18,000	88,000
Abandonment and impairment of unproved properties	269,725,000	30,076,000	47,619,000
Derivative fair value (income) loss	(213,350,000)	261,391,000	(416,364,000)
Cash settlements on derivative financial instruments	13,117,000	347,336,000	532,122,000
Allowance for bad debt	1,550,000	800,000	2,300,000
Amortization of deferred financing costs, loss on extinguishment of debt and other	5,445,000	7,170,000	29,383,000
Deferred and stock-based compensation	30,706,000	74,685,000	(20,411,000)
(Gain) loss on the sale of assets	(23,716,000)	7,074,000	406,856,000
Changes in working capital:
Accounts receivable	(102,866,000)	(20,586,000)	64,704,000
Inventory and other	(2,979,000)	6,220,000	(14,868,000)
Accounts payable	45,912,000	(27,259,000)	(26,197,000)
Accrued liabilities and other	12,764,000	(64,763,000)	(32,768,000)
Net cash provided from operating activities	816,254,000	387,068,000	691,402,000
Investing activities:
Additions to natural gas and oil properties	(1,148,613,000)	(466,252,000)	(1,030,644,000)
Additions to field service assets	(5,710,000)	(3,052,000)	(4,441,000)
Acreage purchases	(58,213,000)	(43,482,000)	(74,880,000)
MRD Merger, net of cash acquired	0	7,180,000	0
Other	0	0	(75,000)
Proceeds from disposal of assets	72,468,000	193,755,000	890,901,000
Purchases of marketable securities held by the deferred compensation plan	(88,167,000)	(37,019,000)	(28,876,000)
Proceeds from the sales of marketable securities held by the deferred compensation plan	89,178,000	40,035,000	29,243,000
Net cash used in investing activities	(1,139,057,000)	(308,835,000)	(218,772,000)
Financing activities:
Borrowings on credit facilities	2,041,000,000	2,274,000,000	2,271,000,000
Repayments on credit facilities	(1,712,000,000)	(1,487,000,000)	(2,899,000,000)
Issuance of senior notes	0	0	750,000,000
Repayment of senior or senior subordinated notes	(500,000)	(273,012,000)	(516,875,000)
Dividends paid	(19,839,000)	(16,682,000)	(27,083,000)
Debt issuance costs	(403,000)	(6,342,000)	(14,156,000)
Taxes paid for shares withheld	(6,983,000)	(3,849,000)	(7,702,000)
Change in cash overdrafts	17,180,000	18,393,000	(37,089,000)
Proceeds from the sales of common stock held by the deferred compensation plan	4,482,000	13,102,000	8,298,000
Net cash provided from (used in) financing activities	322,937,000	(78,390,000)	(472,607,000)
Increase (decrease) in cash and cash equivalents	134,000	(157,000)	23,000
Cash and cash equivalents at beginning of year	314,000	471,000	448,000
Cash and cash equivalents at end of year	448,000	314,000	471,000
MRD
Financing activities:
Repayments on credit facilities	$ 0	$ (597,000,000)	$ 0