Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
OPERATING ACTIVITIES:
Net income (loss)	$ (728,024)	$ 178,827
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion, and amortization	279,739	294,412
Impairments (Notes 2 and 3)	1,149,367	0
(Gain) loss on derivatives (Note 10)	(12,917)	9,234
Cash receipts (payments) on derivatives settled (Note 10)	32,156	(18,984)
Deferred tax expense (benefit)	(437,220)	87,802
(Gain) loss on disposition of assets	6,270	(9,092)
Employee stock compensation plans	12,514	17,780
Other, net	1,834	5,156
Changes in operating assets and liabilities increasing (decreasing) cash:
Accounts receivable	84,098	(47,704)
Accounts payable	(4,432)	1,708
Material and supplies	(2,114)	2,222
Accrued liabilities	(363)	28,596
Other, net	574	(430)
Net cash provided by operating activities	381,482	549,527
INVESTING ACTIVITIES:
Capital expenditures	(484,028)	(686,405)
Proceeds from disposition of assets	9,838	49,341
Other	0	303
Net cash used in investing activities	(474,190)	(636,761)
FINANCING ACTIVITIES:
Borrowings under credit agreement	484,600	395,700
Payments under credit agreement	(388,900)	(364,900)
Payments on capitalized leases	(2,648)	(1,505)
Proceeds from exercise of stock options	4	926
Book overdrafts	(503)	39,315
Net cash provided by financing activities	92,553	69,536
Net decrease in cash and cash equivalents	(155)	(17,698)
Cash and cash equivalents, beginning of period	1,049	18,593
Cash and cash equivalents, end of period	894	895
Cash paid during the year for:
Interest paid (net of capitalized)	12,691	(1,340)
Income taxes	3,277	16,000
Changes in accounts payable and accrued liabilities related to purchases of property, plant, and equipment	116,062	(42,651)
Non-cash reductions to oil and natural gas properties related to asset retirement obligations	8,558	40,516
Non-cash additions to property, plant, and equipment acquired under capital leases	$ 0	$ (28,202)