Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues and other income
Oil, natural gas, and related product sales	$ 340,021	$ 266,178
CO2 sales and transportation fees	7,552	5,388
Interest income and other income	5,661	3,888
Total revenues and other income	353,234	275,454
Expenses
Lease operating expenses	118,356	113,840
Marketing and plant operating expenses	12,424	14,065
CO2 discovery and operating expenses	462	593
Taxes other than income	27,319	22,440
General and administrative expenses	20,232	28,241
Interest, net of amounts capitalized of $8,452 and $4,654, respectively	17,239	27,178
Depletion, depreciation, and amortization	52,451	51,195
Commodity derivatives expense (income)	48,825	(24,602)
Other expenses	2,328	0
Total expenses	299,636	232,950
Income before income taxes	53,598	42,504
Income tax provision	14,020	20,974
Net income	$ 39,578	$ 21,530
Net income per common share
Basic	$ 0.10	$ 0.06
Diluted	$ 0.09	$ 0.05
Weighted average common shares outstanding
Basic	392,742	389,397
Diluted	451,543	392,997