CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) (in thousands, except per share amounts) - USD ($) shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Operating revenues and other income:
Oil, gas, and NGL production revenue	$ 294,459,000	$ 329,165,000	$ 912,596,000	$ 832,130,000
Net gain (loss) on divestiture activity	(1,895,000)	22,388,000	(131,565,000)	3,413,000
Other operating revenues	2,815,000	1,107,000	7,807,000	2,007,000
Total operating revenues and other income	295,379,000	352,660,000	788,838,000	837,550,000
Operating expenses:
Oil, gas, and NGL production expense	122,651,000	152,524,000	385,073,000	445,658,000
Depletion, depreciation, amortization, and asset retirement obligation liability accretion	134,599,000	193,966,000	425,643,000	619,193,000
Exploration	14,243,000	13,482,000	39,293,000	41,942,000
Impairment of proved properties	0	8,049,000	3,806,000	277,834,000
Abandonment and impairment of unproved properties	0	3,568,000	157,000	5,917,000
General and administrative	27,880,000	32,679,000	85,564,000	93,117,000
Net derivative (gain) loss	80,599,000	(28,037,000)	(89,364,000)	121,086,000
Other Operating Income (Expense), Net	999,000	(5,917,000)	6,303,000	7,731,000
Total operating expenses	380,971,000	370,314,000	856,475,000	1,612,478,000
Loss from operations	(85,592,000)	(17,654,000)	(67,637,000)	(774,928,000)
Non-operating income (expense):
Interest expense	(44,091,000)	(47,206,000)	(135,639,000)	(112,329,000)
Gain (loss) on extinguishment of debt	0	0	(35,000)	15,722,000
Other, net	1,301,000	221,000	2,901,000	232,000
Loss before income taxes	(128,382,000)	(64,639,000)	(200,410,000)	(871,303,000)
Income tax benefit	39,270,000	23,732,000	65,825,000	314,505,000
Net loss	$ (89,112,000)	$ (40,907,000)	$ (134,585,000)	$ (556,798,000)
Basic weighted-average common shares outstanding	111,575	78,468	111,366	71,574
Diluted weighted-average common shares outstanding	111,575	78,468	111,366	71,574
Basic net loss per common share	$ (0.80)	$ (0.52)	$ (1.21)	$ (7.78)
Diluted net loss per common share	(0.80)	(0.52)	(1.21)	(7.78)
Dividends per common share	$ 0.05	$ 0.05	$ 0.10	$ 0.10