Consolidated Statement of Operations - USD ($) shares in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues
Oil and gas revenues									$ 635,505,000	$ 721,672,000	$ 1,304,004,000
Midstream revenues									35,406,000	23,769,000	11,614,000
Well services revenues									33,754,000	44,294,000	74,610,000
Total revenues	$ 217,991,000	$ 177,311,000	$ 179,080,000	$ 130,283,000	$ 182,067,000	$ 197,235,000	$ 230,046,000	$ 180,387,000	704,665,000	789,735,000	1,390,228,000
Operating expenses
Lease operating expenses									135,444,000	144,481,000	169,600,000
Midstream operating expenses									9,003,000	6,198,000	4,647,000
Well services operating expenses									17,009,000	21,833,000	45,605,000
Marketing, transportation and gathering expenses									40,366,000	31,610,000	29,133,000
Production taxes									56,565,000	69,584,000	127,648,000
Depreciation, depletion and amortization									476,331,000	485,322,000	412,334,000
Exploration expenses									1,785,000	2,369,000	3,064,000
Rig termination									0	3,895,000	0
Impairment									4,684,000	46,109,000	47,238,000
General and administrative expenses									93,008,000	92,498,000	92,306,000
Total operating expenses									834,195,000	903,899,000	931,575,000
Gain (loss) on sale of properties									(1,303,000)	0	186,999,000
Operating income (loss)	(1,702,000)	(25,702,000)	(28,214,000)	(75,215,000)	(53,166,000)	(19,926,000)	(7,437,000)	(33,635,000)	(130,833,000)	(114,164,000)	645,652,000
Other income (expense)
Net gain (loss) on derivative instruments									(105,317,000)	210,376,000	327,011,000
Interest expense, net of capitalized interest									(140,305,000)	(149,648,000)	(158,390,000)
Gain on extinguishment of debt									4,741,000	0	0
Other income (expense)									160,000	(2,935,000)	195,000
Total other income (expense)									(240,721,000)	57,793,000	168,816,000
Income (loss) before income taxes									(371,554,000)	(56,371,000)	814,468,000
Income tax benefit									128,538,000	16,123,000	(307,591,000)
Net income (loss)	$ (54,688,000)	$ (33,942,000)	$ (89,931,000)	$ (64,455,000)	$ 3,968,000	$ 27,055,000	$ (53,230,000)	$ (18,041,000)	$ (243,016,000)	$ (40,248,000)	$ 506,877,000
Earnings (loss) per share:
Basic (in dollars per share)	$ (0.25)	$ (0.19)	$ (0.51)	$ (0.40)	$ 0.03	$ 0.20	$ (0.39)	$ (0.17)	$ (1.32)	$ (0.31)	$ 5.09
Diluted (in dollars per share)	$ (0.25)	$ (0.19)	$ (0.51)	$ (0.40)	$ 0.03	$ 0.20	$ (0.39)	$ (0.17)	$ (1.32)	$ (0.31)	$ 5.05
Weighted average shares outstanding:
Basic (in shares)									183,615	130,186	99,677
Diluted (in shares)									183,615	130,186	100,365