CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenues:
Oil sales	$ 162,005	$ 259,344	$ 279,578	$ 455,349
Gas sales	76,615	106,374	159,223	217,336
NGL sales	51,939	49,477	85,291	95,077
Gas gathering and other	8,211	9,141	15,452	17,411
Gas marketing, net	103	(53)	(71)	112
Total revenues	298,873	424,283	539,473	785,285
Costs and expenses:
Impairment of oil and gas properties	399,194	967,287	629,326	1,570,886
Depreciation, depletion and amortization	123,877	217,451	251,976	434,229
Asset retirement obligation	1,750	2,042	4,048	3,778
Production	57,213	70,600	127,915	152,811
Transportation, processing and other operating	44,436	43,713	90,879	83,355
Gas gathering and other	7,492	11,306	15,572	20,170
Taxes other than income	14,066	25,980	27,905	47,961
General and administrative	21,424	14,054	35,321	29,992
Stock compensation	7,490	4,988	13,018	10,143
(Gain) loss on derivative instruments, net	33,236		32,808
Other operating, net	24	260	114	784
Total costs and expenses	710,202	1,357,681	1,228,882	2,354,109
Operating income (loss)	(411,329)	(933,398)	(689,409)	(1,568,824)
Other (income) and expense:
Interest expense	20,824	21,297	41,629	42,553
Capitalized interest	(5,633)	(8,570)	(10,537)	(17,987)
Other, net	(2,011)	(3,854)	(3,661)	(7,439)
Income (loss) before income tax	(424,509)	(942,271)	(716,840)	(1,585,951)
Income tax expense (benefit)	(154,219)	(342,056)	(260,419)	(570,795)
Net income (loss)	$ (270,290)	$ (600,215)	$ (456,421)	$ (1,015,156)
Earnings (loss) per share to common stockholders:
Basic (in dollars per share)	$ (2.91)	$ (6.47)	$ (4.91)	$ (10.94)
Diluted (in dollars per share)	(2.91)	(6.47)	(4.91)	(10.94)
Dividends per share	$ 0.08	$ 0.16	$ 0.16	$ 0.32
Comprehensive income (loss):
Net income (loss)	$ (270,290)	$ (600,215)	$ (456,421)	$ (1,015,156)
Other comprehensive income (loss):
Change in fair value of investments, net of tax	195	(292)	280	(190)
Total comprehensive income (loss)	$ (270,095)	$ (600,507)	$ (456,141)	$ (1,015,346)