Condensed Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net income (loss)	$ (44,216)	$ 330,373
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	361,430	295,520
Gain on sale of properties	(172)	(187,076)
Impairment of oil and gas properties	24,917	2,243
Deferred income taxes	(17,829)	197,548
Derivative instruments	(111,285)	(20,253)
Stock-based compensation expenses	19,629	15,755
Deferred financing costs amortization and other	7,468	5,209
Working capital and other changes:
Change in accounts receivable	108,309	(62,581)
Change in inventory	8,425	(4,089)
Change in prepaid expenses	638	(3,179)
Change in other current assets	5,529	(1,581)
Change in other assets	0	(3,069)
Change in accounts payable and accrued liabilities	(84,133)	108,788
Change in other current liabilities	1,655	0
Change in other liabilities	(28)	(116)
Net cash provided by operating activities	280,337	673,492
Cash flows from investing activities:
Capital expenditures	(740,633)	(998,889)
Proceeds from sale of properties	78	324,938
Costs related to sale of properties	0	(2,337)
Derivative settlements	291,436	(24,773)
Advances from joint interest partners	(1,239)	(6,053)
Net cash used in investing activities	(450,358)	(707,114)
Cash flows from financing activities:
Proceeds from sale of common stock	462,833	0
Proceeds from revolving credit facility	618,000	370,000
Principal payments on revolving credit facility	(938,000)	(355,570)
Deferred financing costs	(3,587)	(99)
Purchases of treasury stock	(2,771)	(5,240)
Other	0	(176)
Net cash provided by financing activities	136,475	8,915
Decrease in cash and cash equivalents	(33,546)	(24,707)
Cash and cash equivalents:
Beginning of period	45,811	91,901
End of period	12,265	67,194
Supplemental non-cash transactions:
Change in accrued capital expenditures	(233,913)	99,103
Change in asset retirement obligations	$ 3,405	$ 5,134