Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenues:
Crude oil, natural gas and NGL sales	$ 110,841	$ 96,928	$ 186,208	$ 171,037
Sales from natural gas marketing	1,879	2,523	4,050	5,756
Commodity price risk management gain (loss), net	(92,801)	(49,041)	(81,745)	17,621
Well operations, pipeline income and other	178	550	2,415	1,178
Total revenues	20,097	50,960	110,928	195,592
Costs, expenses and other:
Production costs	13,675	12,639	29,005	28,924
Production taxes	6,043	3,837	10,114	7,730
Transportation, gathering and processing expenses	4,465	1,308	8,506	2,646
Cost of natural gas marketing	2,125	2,836	4,703	6,094
Exploration expense	237	275	447	560
Impairment of crude oil and natural gas properties	4,170	4,404	5,171	7,176
General and administrative expense	23,579	20,728	46,358	41,773
Depreciation, depletion and amortization	107,014	70,106	204,402	125,926
Allowance for uncollectible notes receivable	0	0	44,738	0
Accretion of asset retirement obligation	1,811	1,588	3,623	3,148
(Gain) loss on sale of properties and equipment	260	(207)	176	(228)
Total cost, expenses and other	163,379	117,514	357,243	223,749
Income (loss) from operations	(143,282)	(66,554)	(246,315)	(28,157)
Interest expense	(10,672)	(11,567)	(22,566)	(23,292)
Interest income	177	1,135	1,735	2,248
Income (loss) before income taxes	(153,777)	(76,986)	(267,146)	(49,201)
Provision for income taxes	58,327	30,116	100,166	19,393
Net income (loss)	$ (95,450)	$ (46,870)	$ (166,980)	$ (29,808)
Earnings per share:
Basic	$ (2.04)	$ (1.17)	$ (3.78)	$ (0.78)
Diluted	$ (2.04)	$ (1.17)	$ (3.78)	$ (0.78)
Weighted-average common shares outstanding
Basic	46,742	40,035	44,175	38,202
Diluted	46,742	40,035	44,175	38,202