Derivative Financial Instruments (Fair Value Of Oil And Natural Gas Derivative Financial Instruments) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Fair Value of Derivative Financial Instruments	$ (29,802)	$ (6,535)
Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Fair Value of Derivative Financial Instruments	(16,867)
Oil [Member]
Derivatives, Fair Value [Line Items]
Fair Value of Derivative Financial Instruments	(12,935)
Swap [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Natural Gas Mmbtu		112,348,000
Swap [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Volume (oil)		2,192,000
Swap [Member] | 2015 [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Natural Gas Mmbtu	28,287,000
Weighted average strike price per Mmbtu/Bbl	4.31
Swap [Member] | 2015 [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Volume (oil)	976,000
Weighted average strike price per Mmbtu/Bbl	93.19
Swap [Member] | 2014 [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Natural Gas Mmbtu	42,371,000
Weighted average strike price per Mmbtu/Bbl	4.22
Swap [Member] | 2014 [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Volume (oil)	829,000
Weighted average strike price per Mmbtu/Bbl	95.03
Basis Swap [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Volume (oil)		274,000
Basis Swap [Member] | 2015 [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Volume (oil)	91,000
Weighted average strike price per Mmbtu/Bbl	6.10
Basis Swap [Member] | 2014 [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Volume (oil)	92,000
Weighted average strike price per Mmbtu/Bbl	6.03
Call Option [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Natural Gas Mmbtu		40,150,000
Call Option [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Volume (oil)		730,000
Call Option [Member] | 2015 [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Natural Gas Mmbtu	20,075,000
Weighted average strike price per Mmbtu/Bbl	4.29
Call Option [Member] | 2015 [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Volume (oil)	365,000
Weighted average strike price per Mmbtu/Bbl	100.00
Call Option [Member] | 2014 [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Natural Gas Mmbtu	10,120,000
Weighted average strike price per Mmbtu/Bbl	4.29
Call Option [Member] | 2014 [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Volume (oil)	184,000
Weighted average strike price per Mmbtu/Bbl	100.00
Basis Swap [Member] | 2015 [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Fair Value of Derivative Financial Instruments	288
Basis Swap [Member] | 2014 [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Fair Value of Derivative Financial Instruments	297
Call Option [Member] | 2015 [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Fair Value of Derivative Financial Instruments	(6,837)
Call Option [Member] | 2015 [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Fair Value of Derivative Financial Instruments	(1,508)
Call Option [Member] | 2014 [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Fair Value of Derivative Financial Instruments	(3,096)
Call Option [Member] | 2014 [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Fair Value of Derivative Financial Instruments	(920)
Swap [Member] | 2015 [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Fair Value of Derivative Financial Instruments	2,666
Swap [Member] | 2015 [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Fair Value of Derivative Financial Instruments	(4,221)
Swap [Member] | 2014 [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Fair Value of Derivative Financial Instruments	(9,600)
Swap [Member] | 2014 [Member] | Oil [Member]
Derivatives, Fair Value [Line Items]
Fair Value of Derivative Financial Instruments	$ (6,871)