Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues and other income
Oil, natural gas, and related product sales	$ 290,388	$ 622,005	$ 954,749	$ 1,902,880
CO2 and helium sales and transportation fees	9,144	11,378	23,268	33,961
Interest income and other income	4,068	4,274	9,926	14,680
Total revenues and other income	303,600	637,657	987,943	1,951,521
Expenses
Lease operating expenses	113,902	155,198	387,156	488,827
Marketing and plant operating expenses	14,458	15,328	40,358	50,263
CO2 and helium discovery and operating expenses	1,017	11,434	2,909	22,229
Taxes other than income	25,607	39,966	85,841	136,761
General and administrative expenses	32,907	40,366	117,134	123,011
Interest, net of amounts capitalized of $8,081, $5,862, $25,228, and $17,413, respectively	39,225	44,752	119,187	140,136
Depletion, depreciation, and amortization	121,406	146,560	419,304	435,854
Commodity derivatives expense (income)	(92,028)	(252,265)	(126,178)	(825)
Loss on early extinguishment of debt	0	0	0	113,908
Write-down of oil and natural gas properties	1,760,600	0	3,612,600	0
Impairment of goodwill	1,261,512	0	1,261,512	0
Total expenses	3,278,606	201,339	5,919,823	1,510,164
Income (loss) before income taxes	(2,975,006)	436,318	(4,931,880)	441,357
Income tax provision (benefit)	(730,880)	167,570	(1,431,509)	169,499
Net income (loss)	$ (2,244,126)	$ 268,748	$ (3,500,371)	$ 271,858
Net income (loss) per common share
Basic	$ (6.41)	$ 0.77	$ (10.01)	$ 0.78
Diluted	(6.41)	0.77	(10.01)	0.77
Dividends declared per common share	$ 0.0625	$ 0.0625	$ 0.1875	$ 0.1875
Weighted average common shares outstanding
Basic	350,052	348,454	349,787	348,993
Diluted	350,052	350,918	349,787	351,347