Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues:
Crude oil, natural gas and NGL sales	$ 141,805	$ 104,483	$ 328,013	$ 275,520
Sales from natural gas marketing	2,678	2,580	6,728	8,336
Commodity price risk management gain (loss), net	19,397	123,549	(62,348)	141,170
Well operations, pipeline income and other	10	488	2,425	1,666
Total revenues	163,890	231,100	274,818	426,692
Costs, expenses and other:
Production costs	14,001	13,825	43,006	42,749
Production taxes	9,568	5,476	19,682	13,206
Transportation, gathering and processing expenses	5,048	3,938	13,554	6,584
Cost of natural gas marketing	3,092	2,781	7,795	8,875
Exploration expense	241	252	688	812
Impairment of crude oil and natural gas properties	933	154,031	6,104	161,207
General and administrative expense	32,510	20,277	78,868	62,050
Depreciation, depletion and amortization	112,927	80,947	317,329	206,873
Allowance for uncollectible notes receivable	(700)	0	44,038	0
Accretion of asset retirement obligation	1,777	1,594	5,400	4,742
(Gain) loss on sale of properties and equipment	(219)	(74)	(43)	(302)
Total cost, expenses and other	179,178	283,047	536,421	506,796
Income (loss) from operations	(15,288)	(51,947)	(261,603)	(80,104)
Interest expense	(20,193)	(12,092)	(42,759)	(35,384)
Interest income	140	1,378	1,875	3,626
Income (loss) before income taxes	(35,341)	(62,661)	(302,487)	(111,862)
Provision for income taxes	12,032	21,167	112,198	40,560
Net income (loss)	$ (23,309)	$ (41,494)	$ (190,289)	$ (71,302)
Earnings per share:
Basic	$ (0.48)	$ (1.04)	$ (4.16)	$ (1.84)
Diluted	$ (0.48)	$ (1.04)	$ (4.16)	$ (1.84)
Weighted-average common shares outstanding
Basic	48,839	40,085	45,741	38,837
Diluted	48,839	40,085	45,741	38,837