Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
OPERATING ACTIVITIES:
Net income (loss)	$ (522,743)	$ 111,305
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion, and amortization	196,576	190,813
Impairments (Notes 2 and 3)	819,443	0
(Gain) loss on derivatives	(4,667)	29,075
Cash (payments) receipts on derivatives settled	21,082	(17,955)
Deferred tax expense (benefit)	(315,783)	52,000
Gain on disposition of assets	(960)	(9,621)
Employee stock compensation plans	12,329	11,655
Other, net	1,944	3,076
Changes in operating assets and liabilities increasing (decreasing) cash:
Accounts receivable	77,894	(45,150)
Accounts payable	(16,327)	(11,585)
Material and supplies	(2,366)	2,458
Accrued liabilities	(11,811)	7,440
Other, net	2,995	2,017
Net cash provided by operating activities	257,606	325,528
INVESTING ACTIVITIES:
Capital expenditures	(371,572)	(420,235)
Proceeds from disposition of assets	5,130	40,825
Other	0	303
Net cash used in investing activities	(366,442)	(379,107)
FINANCING ACTIVITIES:
Borrowings under credit agreement	396,000	129,300
Payments under credit agreement	(281,500)	(129,300)
Payments on capitalized leases	(1,757)	(711)
Proceeds from exercise of stock options	4	887
Book overdrafts	(4,121)	35,888
Net cash provided by financing activities	108,626	36,064
Net decrease in cash and cash equivalents	(210)	(17,515)
Cash and cash equivalents, beginning of period	1,049	18,593
Cash and cash equivalents, end of period	839	1,078
Cash paid during the year for:
Interest paid (net of capitalized)	15,886	6,223
Income taxes	3,142	15,800
Changes in accounts payable and accrued liabilities related to purchases of property, plant, and equipment	92,743	(29,247)
Non-cash reductions to oil and natural gas properties related to asset retirement obligations	5,956	15,432
Non-cash additions to property, plant, and equipment acquired under capital leases	$ 0	$ (26,510)