Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues
Oil, natural gas liquids and natural gas sales	$ 176,375	$ 122,764
Gain on derivative instruments, net	64,546	5,455
Total revenues	240,921	128,219
Operating Costs and Expenses
Oil, natural gas liquids and natural gas production	41,288	47,727
Production and ad valorem taxes	12,820	11,170
Depreciation, depletion and amortization	99,652	119,362
Asset impairment	1,460	220,025
Exploration	3,636	242
General and administrative (including non-cash stock based compensation of $3,197 and $2,471 for the three months ended March 31, 2017 and 2016, respectively)	20,399	29,525
Accretion of discount on asset retirement obligations	1,414	1,757
(Gain) loss on sale of assets and other	(1,175)	222
Total operating costs and expenses	179,494	430,030
Operating Income (Loss)	61,427	(301,811)
Other Income (Expense)
Interest expense	(8,966)	(9,833)
Other income	383	95
Total other expense	(8,583)	(9,738)
Income (Loss) Before Income Taxes	52,844	(311,549)
Income tax expense (benefit)	19,441	(108,433)
Net Income (Loss)	$ 33,403	$ (203,116)
Diluted Earnings Per Average Common Share (in dollars per share)	$ 0.34	$ (2.34)
Basic Earnings Per Average Common Share (in dollars per share)	$ 0.34	$ (2.34)
Diluted Average Common Shares Outstanding (in shares)	97,607	86,632
Basic Average Common Shares Outstanding (in shares)	97,140	86,632