Significant Accounting Policies (Details) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2014 segment	Dec. 31, 2013	Dec. 31, 2012	Dec. 16, 2014
Internal costs capitalized	$ 10,100,000	$ 10,100,000	$ 6,600,000	$ 2,700,000
Average unweighted first day of the month prices of proved reserves		94.99	96.78	2.76
Depletion of Oil and Gas Properties		186,800,000	134,200,000	87,600,000
Depletion (per Mcfe)	2.49	2.49	2.10	1.80
Insurance proceeds		0	600,000	12,700,000
Interest capitalized		6,500,000	13,000,000	4,300,000
Deferred financing costs		19,156,000	6,261,000	19,227,000
Amortization of deferred financing costs		11,341,000	9,587,000	4,020,000
Number of reportable segment		1
Goodwill			173,547,000
Goodwill impairment	173,500,000	173,500,000	0
Asset retirement obligation roll forward
Beginning balance		13,798,000	13,580,000
Liabilities incurred		34,048,000	993,000
Liabilities disposed			(1,678,000)
Liabilities settled		(111,000)	(49,000)
Revisions		89,000
Accretion expense		958,000	952,000
Ending balance	48,782,000	48,782,000	13,798,000	13,580,000
Liabilities assumed		700,000	1,000,000	1,900,000
Other short-term obligations assumed in the combination					15,191,000
Number of Operating Segments		1
Debt Instruments
Amortization of deferred financing costs		9,500,000	9,000,000	3,200,000
Oil and Gas Properties
Ceiling test impairment expense		247,700,000	0
Impairment Charges				641,800,000
Gas Gathering and Processing Facilities
Impairment Charges		1,700,000	0	21,400,000
Minimum
Useful life		3 years
Maximum
Useful life		30 years
Forest Oil Combination
Asset retirement obligation roll forward
Ending balance	33,300,000	33,300,000
Current asset retirement obligation	$ 9,400,000	$ 9,400,000