Fair Value of Derivative and Balance Sheet Location (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Derivatives, Fair Value
Derivative Asset, Fair Value, Gross Asset	$ 27,186	$ 6,024
Derivative Liability, Fair Value, Gross Liability	4,597	17,531
Current Assets
Derivatives, Fair Value
Derivative Asset, Fair Value, Gross Asset	9,147	1,521
Non Current Assets
Derivatives, Fair Value
Derivative Asset, Fair Value, Gross Asset	18,039	4,503
Current Liabilities
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	2,356	14,689
Non Current Liabilities
Derivatives, Fair Value
Derivative Liability, Fair Value, Gross Liability	2,241	2,842
Commodity Contracts Related to Natural Gas and Crude Oil Sales | Current Assets
Derivatives, Fair Value
Fair Value of Derivatives	8,761	1,086
Commodity Contracts Related to Natural Gas and Crude Oil Sales | Non Current Assets
Derivatives, Fair Value
Fair Value of Derivatives	17,855	4,225
Commodity Contracts Related to Natural Gas and Crude Oil Sales | Current Liabilities
Derivatives, Fair Value
Fair Value of Derivatives	1,948	14,437
Commodity Contracts Related to Natural Gas and Crude Oil Sales | Non Current Liabilities
Derivatives, Fair Value
Fair Value of Derivatives	2,077	2,609
Commodity Contracts Related to Natural Gas Marketing | Current Assets
Derivatives, Fair Value
Fair Value of Derivatives	386	361
Commodity Contracts Related to Natural Gas Marketing | Non Current Assets
Derivatives, Fair Value
Fair Value of Derivatives	184	278
Commodity Contracts Related to Natural Gas Marketing | Current Liabilities
Derivatives, Fair Value
Fair Value of Derivatives	334	247
Commodity Contracts Related to Natural Gas Marketing | Non Current Liabilities
Derivatives, Fair Value
Fair Value of Derivatives	157	233
Basis Protection Contracts Related to Natural Gas and Crude Oil Sales | Current Assets
Derivatives, Fair Value
Fair Value of Derivatives	0	74
Basis Protection Contracts Related to Natural Gas and Crude Oil Sales | Current Liabilities
Derivatives, Fair Value
Fair Value of Derivatives	74	0
Basis Protection Contracts Related to Natural Gas and Crude Oil Sales | Non Current Liabilities
Derivatives, Fair Value
Fair Value of Derivatives	7	0
Basis Protection Contracts Related to Natural Gas Marketing [Member] | Current Liabilities
Derivatives, Fair Value
Fair Value of Derivatives	$ 0	$ 5