Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenues:
Crude oil, natural gas and NGL sales	$ 75,367	$ 74,109
Sales from natural gas marketing	2,171	3,233
Commodity price risk management gain (loss), net	11,056	66,662
Well operations, pipeline income and other	2,237	628
Total revenues	90,831	144,632
Costs, expenses and other:
Production costs	15,330	16,285
Production taxes	4,071	3,893
Transportation, gathering and processing expenses	4,041	1,338
Cost of natural gas marketing	2,578	3,258
Exploration expense	210	285
Impairment of crude oil and natural gas properties	1,001	2,772
General and administrative expense	22,779	21,045
Depreciation, depletion and amortization	97,388	55,820
Allowance for uncollectible notes receivable	44,738	0
Accretion of asset retirement obligation	1,812	1,560
(Gain) loss on sale of properties and equipment	(84)	(21)
Total cost, expenses and other	193,864	106,235
Income (loss) from operations	(103,033)	38,397
Interest expense	(11,894)	(11,725)
Interest income	1,558	1,113
Income (loss) before income taxes	(113,369)	27,785
Provision for income taxes	41,839	(10,723)
Net income (loss)	$ (71,530)	$ 17,062
Earnings per share:
Basic	$ (1.72)	$ 0.47
Diluted	$ (1.72)	$ 0.46
Weighted-average common shares outstanding
Basic	41,608	36,349
Diluted	41,608	36,981