Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
OPERATING ACTIVITIES:
Net loss	$ (113,285)	$ (522,743)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, depletion, and amortization	109,522	196,576
Impairments (Notes 2 and 3)	112,120	819,443
(Gain) loss on derivatives	11,743	(4,667)
Cash receipts on derivatives settled	12,192	21,082
Deferred tax benefit	(58,560)	(315,783)
Gain on disposition of assets	(946)	(960)
Employee stock compensation plans	7,703	12,329
Other, net	(2,755)	1,944
Changes in operating assets and liabilities increasing (decreasing) cash:
Accounts receivable	5,443	77,894
Accounts payable	24,077	(16,327)
Material and supplies	241	(2,366)
Accrued liabilities	3,411	(11,811)
Income taxes	18,969	(1,845)
Other, net	2,841	4,840
Net cash provided by operating activities	132,716	257,606
INVESTING ACTIVITIES:
Capital expenditures	(124,182)	(371,572)
Proceeds from disposition of assets	46,627	5,130
Other	169	0
Net cash used in investing activities	(77,386)	(366,442)
FINANCING ACTIVITIES:
Borrowings under credit agreement	150,300	396,000
Payments under credit agreement	(195,300)	(281,500)
Payments on capitalized leases	(1,828)	(1,757)
Tax (benefit) expense from stock compensation	(376)	4
Book overdrafts	(7,987)	(4,121)
Net cash (used in) provided by financing activities	(55,191)	108,626
Net increase (decrease) in cash and cash equivalents	139	(210)
Cash and cash equivalents, beginning of period	835	1,049
Cash and cash equivalents, end of period	974	839
Cash paid during the year for:
Interest paid (net of capitalized)	19,830	15,886
Income taxes	0	3,142
Changes in accounts payable and accrued liabilities related to purchases of property, plant, and equipment	30,758	92,743
Non-cash reductions to oil and natural gas properties related to asset retirement obligations	$ 28,884	$ 5,956