Guarantor Financial Statements - Condensed Consolidating Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating revenue:
Oil production	$ 71,116	$ 105,013	$ 204,102	$ 324,105
Natural gas production	15,601	17,367	43,327	72,611
Natural gas liquids production	6,666	5,980	15,119	29,379
Other operational income	1,044	1,392	1,737	3,184
Derivative income, net	0	2,444	0	4,871
Total operating revenue	94,427	132,196	264,285	434,150
Operating expenses:
Lease operating expenses	16,976	24,244	55,349	79,250
Transportation, processing and gathering expenses	10,633	18,208	18,657	55,851
Production taxes	835	2,052	1,894	6,394
Depreciation, depletion and amortization	58,918	61,936	166,707	226,309
Write-down of oil and gas properties	36,484	295,679	284,337	1,011,385
Accretion expense	10,082	6,498	30,147	19,315
Salaries, general and administrative expenses	15,425	19,552	48,193	52,977
Incentive compensation expense	2,160	794	11,809	3,621
Restructuring fees	5,784	0	16,173	0
Other operational expenses	9,059	442	49,266	1,612
Derivative expense, net	199	0	687	0
Total operating expenses	166,555	429,405	683,219	1,456,714
Loss from operations	(72,128)	(297,209)	(418,934)	(1,022,564)
Other (income) expenses:
Interest expense	16,924	10,872	49,764	31,709
Interest income	(58)	(47)	(474)	(235)
Other income	(272)	(411)	(840)	(1,167)
Other expense	16	148	27	148
(Income) loss from investment in subsidiaries	0	0	0	0
Total other expenses	16,610	10,562	48,477	30,455
Loss before income taxes	(88,738)	(307,771)	(467,411)	(1,053,019)
Provision (benefit) for income taxes:
Current	(991)	0	(4,178)	0
Deferred	1,888	(15,806)	10,947	(280,760)
Total income taxes	897	(15,806)	6,769	(280,760)
Net loss	(89,635)	(291,965)	(474,180)	(772,259)
Comprehensive income (loss)	(93,102)	(297,564)	(488,214)	(820,517)
Eliminations
Operating revenue:
Oil production	0	0	0	0
Natural gas production	0	0	0	0
Natural gas liquids production	0	0	0	0
Other operational income	0	0	0	0
Derivative income, net		0		0
Total operating revenue	0	0	0	0
Operating expenses:
Lease operating expenses	0	0	0	0
Transportation, processing and gathering expenses	0	0	0	0
Production taxes	0	0	0	0
Depreciation, depletion and amortization	0	0	0	0
Write-down of oil and gas properties	0	0	0	0
Accretion expense	0	0	0	0
Salaries, general and administrative expenses	0	0	0	0
Incentive compensation expense	0	0	0	0
Restructuring fees	0		0
Other operational expenses	0	0	0	0
Derivative expense, net	0		0
Total operating expenses	0	0	0	0
Loss from operations	0	0	0	0
Other (income) expenses:
Interest expense	0	0	0	0
Interest income	0	0	0	0
Other income	0	0	0	0
Other expense	0	0	0	0
(Income) loss from investment in subsidiaries	(19,301)	211,701	(256,474)	227,957
Total other expenses	(19,301)	211,701	(256,474)	227,957
Loss before income taxes	19,301	(211,701)	256,474	(227,957)
Provision (benefit) for income taxes:
Current	0		0
Deferred	0	0	0	0
Total income taxes	0	0	0	0
Net loss	19,301	(211,701)	256,474	(227,957)
Comprehensive income (loss)	19,301	(211,701)	256,474	(227,957)
Parent
Operating revenue:
Oil production	3,587	1,633	4,971	12,487
Natural gas production	7,216	7,111	13,642	39,375
Natural gas liquids production	5,737	3,502	9,246	21,458
Other operational income	1,044	1,392	1,737	3,184
Derivative income, net		0		0
Total operating revenue	17,584	13,638	29,596	76,504
Operating expenses:
Lease operating expenses	2,771	2,680	9,313	12,767
Transportation, processing and gathering expenses	9,607	13,697	17,174	47,779
Production taxes	669	1,777	1,311	5,411
Depreciation, depletion and amortization	26,388	27,518	45,452	113,682
Write-down of oil and gas properties	1	295,679	15,859	966,216
Accretion expense	58	92	174	274
Salaries, general and administrative expenses	15,425	19,348	48,392	52,747
Incentive compensation expense	2,160	794	11,809	3,621
Restructuring fees	5,784		16,173
Other operational expenses	9,214	142	43,059	1,312
Derivative expense, net	0		0
Total operating expenses	72,077	361,727	208,716	1,203,809
Loss from operations	(54,493)	(348,089)	(179,120)	(1,127,305)
Other (income) expenses:
Interest expense	16,924	10,871	49,764	31,687
Interest income	(43)	(39)	(459)	(186)
Other income	(64)	(117)	(123)	(437)
Other expense	16	148	27	148
(Income) loss from investment in subsidiaries	19,300	(227,973)	250,029	(273,147)
Total other expenses	36,133	(217,110)	299,238	(241,935)
Loss before income taxes	(90,626)	(130,979)	(478,358)	(885,370)
Provision (benefit) for income taxes:
Current	(991)		(4,178)
Deferred	0	160,986	0	(113,111)
Total income taxes	(991)	160,986	(4,178)	(113,111)
Net loss	(89,635)	(291,965)	(474,180)	(772,259)
Comprehensive income (loss)	(93,102)	(297,564)	(488,214)	(820,517)
Guarantor Subsidiary
Operating revenue:
Oil production	67,529	103,380	199,131	311,618
Natural gas production	8,385	10,256	29,685	33,236
Natural gas liquids production	929	2,478	5,873	7,921
Other operational income	0	0	0	0
Derivative income, net		2,444		4,871
Total operating revenue	76,843	118,558	234,689	357,646
Operating expenses:
Lease operating expenses	14,205	21,562	46,023	66,481
Transportation, processing and gathering expenses	1,026	4,511	1,483	8,072
Production taxes	166	275	583	983
Depreciation, depletion and amortization	32,530	34,418	121,255	112,627
Write-down of oil and gas properties	36,483	0	268,128	0
Accretion expense	10,024	6,406	29,973	19,041
Salaries, general and administrative expenses	0	200	(199)	201
Incentive compensation expense	0	0	0	0
Restructuring fees	0		0
Other operational expenses	(155)	300	125	300
Derivative expense, net	199		687
Total operating expenses	94,478	67,672	468,058	207,705
Loss from operations	(17,635)	50,886	(233,369)	149,941
Other (income) expenses:
Interest expense	0	1	0	22
Interest income	(15)	(7)	(15)	(42)
Other income	(208)	(294)	(717)	(727)
Other expense	0	0	0	0
(Income) loss from investment in subsidiaries	0	0	0	0
Total other expenses	(223)	(300)	(732)	(747)
Loss before income taxes	(17,412)	51,186	(232,637)	150,688
Provision (benefit) for income taxes:
Current	0		0
Deferred	1,888	(193,059)	10,947	(167,649)
Total income taxes	1,888	(193,059)	10,947	(167,649)
Net loss	(19,300)	244,245	(243,584)	318,337
Comprehensive income (loss)	(19,300)	244,245	(243,584)	318,337
Non- Guarantor Subsidiaries
Operating revenue:
Oil production	0	0	0	0
Natural gas production	0	0	0	0
Natural gas liquids production	0	0	0	0
Other operational income	0	0	0	0
Derivative income, net		0		0
Total operating revenue	0	0	0	0
Operating expenses:
Lease operating expenses	0	2	13	2
Transportation, processing and gathering expenses	0	0	0	0
Production taxes	0	0	0	0
Depreciation, depletion and amortization	0	0	0	0
Write-down of oil and gas properties	0	0	350	45,169
Accretion expense	0	0	0	0
Salaries, general and administrative expenses	0	4	0	29
Incentive compensation expense	0	0	0	0
Restructuring fees	0		0
Other operational expenses	0	0	6,082	0
Derivative expense, net	0		0
Total operating expenses	0	6	6,445	45,200
Loss from operations	0	(6)	(6,445)	(45,200)
Other (income) expenses:
Interest expense	0	0	0	0
Interest income	0	(1)	0	(7)
Other income	0	0	0	(3)
Other expense	0	0	0	0
(Income) loss from investment in subsidiaries	1	16,272	6,445	45,190
Total other expenses	1	16,271	6,445	45,180
Loss before income taxes	(1)	(16,277)	(12,890)	(90,380)
Provision (benefit) for income taxes:
Current	0		0
Deferred	0	16,267	0	0
Total income taxes	0	16,267	0	0
Net loss	(1)	(32,544)	(12,890)	(90,380)
Comprehensive income (loss)	$ (1)	$ (32,544)	$ (12,890)	$ (90,380)