Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues and other income
Oil, natural gas, and related product sales	$ 266,178	$ 187,803
CO2 sales and transportation fees	5,388	6,272
Interest income and other income	3,888	769
Total revenues and other income	275,454	194,844
Expenses
Lease operating expenses	113,840	102,447
Marketing and plant operating expenses	14,065	13,194
CO2 discovery and operating expenses	593	607
Taxes other than income	22,440	20,092
General and administrative expenses	28,241	33,901
Interest, net of amounts capitalized of $4,654 and $5,780, respectively	27,178	42,171
Depletion, depreciation, and amortization	51,195	77,366
Commodity derivatives expense (income)	(24,602)	22,826
Gain on debt extinguishment	0	(94,991)
Write-down of oil and natural gas properties	0	256,000
Other expenses	0	1,544
Total expenses	232,950	475,157
Income (loss) before income taxes	42,504	(280,313)
Income tax provision (benefit)	20,974	(95,120)
Net income (loss)	$ 21,530	$ (185,193)
Net income (loss) per common share
Basic	$ 0.06	$ (0.53)
Diluted	$ 0.05	$ (0.53)
Weighted average common shares outstanding
Basic	389,397	347,235
Diluted	392,997	347,235