Consolidated statements of operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues:
Total revenues	$ 204,992	$ 208,947
Costs and expenses:
Lease operating expenses	22,040	22,609
Production and ad valorem taxes	9,244	7,219
General and administrative	12,562	21,519
Depletion, depreciation and amortization	61,302	63,098
Impairment expense	186,699	0
Other operating expenses	1,106	1,052
Total costs and expenses	386,964	154,550
Operating income (loss)	(181,972)	54,397
Non-operating income (expense):
Gain (loss) on derivatives, net	297,836	(48,365)
Interest expense	(24,970)	(15,547)
Loss on extinguishment of debt	(13,320)	0
Loss on disposal of assets, net	(602)	(939)
Other income, net	91	867
Total non-operating income (expense), net	259,035	(63,984)
Income (loss) before income taxes	77,063	(9,587)
Income tax (expense) benefit:
Deferred	(2,417)	96
Total income tax (expense) benefit	(2,417)	96
Net income (loss)	$ 74,646	$ (9,491)
Net income (loss) per common share:
Basic (USD per share)	$ 0.32	$ (0.04)
Diluted (USD per share)	$ 0.32	$ (0.04)
Weighted-average common shares outstanding:
Basic (shares)	232,351	230,476
Diluted (shares)	233,458	230,476
Oil sales
Revenues:
Total revenues	$ 119,978	$ 129,171
NGL sales
Revenues:
Total revenues	11,558	32,235
Natural gas sales
Revenues:
Total revenues	4,349	11,970
Midstream service revenues
Revenues:
Total revenues	2,683	2,883
Costs and expenses:
Cost of goods and services sold	1,170	1,603
Sales of purchased oil
Revenues:
Total revenues	66,424	32,688
Costs and expenses:
Cost of goods and services sold	79,297	32,691
Transportation and marketing expenses
Costs and expenses:
Cost of goods and services sold	$ 13,544	$ 4,759