Interim Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	2 Months Ended		3 Months Ended											5 Months Ended	6 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2014	Jun. 03, 2014		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2014		Sep. 30, 2014	[5]	Mar. 31, 2014		Sep. 30, 2013	Jun. 03, 2014	Dec. 31, 2014	Jun. 30, 2013	Mar. 31, 2015	Jun. 30, 2015	Dec. 31, 2013	Dec. 31, 2012
Revenues	$ 50,524	$ 116,909	[1]	$ 109,828	[2]	$ 83,210	[3]	$ 155,638	[4]	$ 194,127		$ 159,491	[6]	$ 183,992	$ 276,400		$ 366,436
Cost and expenses	46,309	140,742	[1]	729,475	[2]	548,278	[3]	850,164	[4]	476,735		112,095	[6]	143,178
Income (loss) from operations	4,215	(23,833)	[1]	(619,647)	[2]	(465,068)	[3]	(694,526)	[4]	(282,608)		47,396	[6]	40,814	23,563		158,244
Net income (loss)	373	$ (36,287)	[1]	(597,265)	[2]	(295,633)	[3]	(454,612)	[4]	(306,356)		$ 13,331	[6]	$ (1,284)	$ (22,956)		$ 98,616
Basic earnings (loss) per share		$ (0.94)	[1]									$ 0.34	[6]	$ (0.03)	$ (0.59)		$ 2.51
Diluted earnings (loss) per share		$ (0.94)	[1]									$ 0.34	[6]	$ (0.03)	$ (0.59)		$ 2.48
Impairments of oil and gas properties				$ 584,200											$ 100	$ 690,300			$ 1,678,800	$ 2,900	$ 8,900
Merger related costs		$ 43,500										$ 2,200
Loss on abandonment activities of non operated interests																				$ 20,800
As Reported [Member]
Revenues	60,143	116,909	[1]			87,253	[7]	156,613	[8]	174,109		159,491	[6]			330,722		$ 417,975
Cost and expenses	46,309	140,742	[1]			575,110	[7]	842,720	[8]	476,735		112,095	[6]			1,319,455		1,894,565
Income (loss) from operations	13,834	(23,833)	[1]			(487,857)	[7]	(686,107)	[8]	(302,626)		47,396	[6]			(988,733)		(1,476,590)
Net income (loss)	$ 6,637	$ (36,287)	[1]			(310,517)	[7]	(449,478)	[8]	$ (319,371)		$ 13,331	[6]			(768,849)		(1,079,366)
Basic earnings (loss) per share		$ (0.94)	[1]									$ 0.34	[6]
Diluted earnings (loss) per share		$ (0.94)	[1]									$ 0.34	[6]
Impairments of oil and gas properties						$ 430,859		$ 682,868								$ 682,868		$ 1,113,727

[1] Included in costs and expenses for the period from April 1, 2014 through June 3, 2014 are merger related costs totaling $43.5 million.

[2] Included in costs and expenses for the three months ended June 30, 2015 is impairment of oil and natural gas properties of $584.2 million.

[3] Included in costs and expenses for the three months ended March 31, 2015 is impairment of oil and natural gas properties of $404.3 million.

[4] Included in costs and expenses for the three months ended December 31, 2014 is impairment of oil and natural gas properties of $690.3 million.

[5] Included in costs and expenses for the three months ended September 30, 2014 is goodwill impairment of $329.3 million.

[6] Included in costs and expenses for the three months ended March 31, 2014 are merger related costs totaling $2.2 million.

[7] Included in costs and expenses for the three months ended March 31, 2015 is impairment of oil and natural gas properties of $430.9 million.

[8] Included in costs and expenses for the three months ended December 31, 2014 is impairment of oil and natural gas properties of $682.8 million.