Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues:
Crude oil, natural gas and NGLs sales	$ 321,099	$ 305,225
Commodity price risk management loss, net	(190,074)	(47,240)
Other income	3,475	2,615
Total revenues	134,500	260,600
Costs, expenses and other:
Lease operating expenses	35,221	29,636
Production taxes	22,168	20,169
Transportation, gathering and processing expenses	11,424	7,313
Exploration, geologic and geophysical expense	2,643	2,646
Impairment of properties and equipment	7,875	33,188
General and administrative expense	39,598	35,696
Depreciation, depletion and amortization	151,422	126,788
Accretion of asset retirement obligations	1,584	1,288
(Gain) loss on sale of properties and equipment	(369)	1,432
Other expenses	3,554	2,768
Total cost, expenses and other	275,120	260,924
Income (loss) from operations	(140,620)	(324)
Interest expense	(16,978)	(17,529)
Interest income	10	148
Income (loss) before income taxes	(157,588)	(17,705)
Income tax (expense) benefit	37,412	4,566
Net income (loss)	$ (120,176)	$ (13,139)
Earnings per share:
Basic	$ (1.82)	$ (0.20)
Diluted	$ (1.82)	$ (0.20)
Weighted-average common shares outstanding
Basic	66,182	65,957
Diluted	66,182	65,957