Subsidiary Guarantor Condensed Consolidating Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues	$ 183,235	$ 163,890	$ 732,100	$ 274,818
Operating Costs and Expenses	55,020		144,828
General and administrative expense	29,299	32,510	85,145	78,868
Exploration, geologic, and geophysical expense	41,908	241	43,895	688
Depreciation, depletion and amortization	125,238	112,927	360,567	317,329
Impairment of Oil and Gas Properties	252,740	933	282,499	3,072
Impairment of goodwill	75,121	0	75,121	0
Provision for uncollectible notes receivable	0	(700)	(40,203)	44,038
Interest Income (Expense), Net	(18,796)		(56,872)
Loss before income taxes	(414,887)	(35,341)	(276,624)	(302,487)
Income tax benefit	122,350	12,032	71,483	112,198
Income (Loss) from Subsidiaries, Net of Tax	0		0
Net loss	(292,537)	$ (23,309)	(205,141)	$ (190,289)
Consolidation, Eliminations [Member]
Revenues	0		0
Operating Costs and Expenses	0		0
General and administrative expense	0		0
Exploration, geologic, and geophysical expense	0		0
Depreciation, depletion and amortization	0		0
Impairment of Oil and Gas Properties	0		0
Impairment of goodwill	0		0
Provision for uncollectible notes receivable			0
Interest Income (Expense), Net	0		0
Loss before income taxes	0		0
Income tax benefit	0		0
Income (Loss) from Subsidiaries, Net of Tax	277,572		297,469
Net loss	277,572		297,469
Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Revenues	33,220		74,998
Operating Costs and Expenses	13,129		26,049
General and administrative expense	3,092		8,792
Exploration, geologic, and geophysical expense	41,691		43,151
Depreciation, depletion and amortization	18,615		43,479
Impairment of Oil and Gas Properties	251,592		280,217
Impairment of goodwill	75,121		75,121
Provision for uncollectible notes receivable			0
Interest Income (Expense), Net	372		685
Loss before income taxes	(369,648)		(401,126)
Income tax benefit	92,076		103,657
Income (Loss) from Subsidiaries, Net of Tax	0		0
Net loss	(277,572)		(297,469)
Parent Company [Member] | Reportable Legal Entities [Member]
Revenues	150,015		657,102
Operating Costs and Expenses	41,891		118,779
General and administrative expense	26,207		76,353
Exploration, geologic, and geophysical expense	217		744
Depreciation, depletion and amortization	106,623		317,088
Impairment of Oil and Gas Properties	1,148		2,282
Impairment of goodwill	0		0
Provision for uncollectible notes receivable			(40,203)
Interest Income (Expense), Net	(19,168)		(57,557)
Loss before income taxes	(45,239)		124,502
Income tax benefit	30,274		(32,174)
Income (Loss) from Subsidiaries, Net of Tax	(277,572)		(297,469)
Net loss	$ (292,537)		$ (205,141)