Derivative Financial Instruments (Gas Volume And Weighted Average Price) (Details)	Dec. 31, 2013
Gas contracts, in MMBTU [Member] | Swap Contracts for Next Twelve Months [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	195,000
Gas contracts, in MMBTU [Member] | Swap Contracts for Year 2 [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	20,000
Gas contracts, in MMBTU [Member] | Swap Contracts for Year 3 [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	0
Gas contracts, in MMBTU [Member] | Collar Contracts With Short Puts for Next Twelve Months [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	115,000
Gas contracts, in MMBTU [Member] | Collar Contracts With Short Puts for Year 2 [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	285,000
Gas contracts, in MMBTU [Member] | Collar Contracts With Short Puts for Year 3 [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	20,000
Gas contracts, in MMBTU [Member] | Basis Swap Contracts for Next Twelve Months [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	85,082	[1]
Gas contracts, in MMBTU [Member] | Basis Swap Contracts for Year 2 [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	30,000	[1]
Gas contracts, in MMBTU [Member] | Basis Swap Contracts for Year 3 [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	0	[1]
Gas contracts, price per MMBTU [Member] | Swap Contracts for Next Twelve Months [Member]
Derivative [Line Items]
Derivative, Swap Type, Average Fixed Price	4.04
Gas contracts, price per MMBTU [Member] | Swap Contracts for Year 2 [Member]
Derivative [Line Items]
Derivative, Swap Type, Average Fixed Price	4.31
Gas contracts, price per MMBTU [Member] | Swap Contracts for Year 3 [Member]
Derivative [Line Items]
Derivative, Swap Type, Average Fixed Price	0.00
Gas contracts, price per MMBTU [Member] | Collar Contracts With Short Puts for Next Twelve Months [Member]
Derivative [Line Items]
Derivative, Average Cap Price	4.70
Derivative, Average Floor Price	4.00
Gas contracts, price per MMBTU [Member] | Collar Contracts With Short Puts for Next Twelve Months [Member] | Short Put [Member]
Derivative [Line Items]
Derivative, Notional Amount, Price Per Unit	3.00
Gas contracts, price per MMBTU [Member] | Collar Contracts With Short Puts for Year 2 [Member]
Derivative [Line Items]
Derivative, Average Cap Price	5.07
Derivative, Average Floor Price	4.00
Gas contracts, price per MMBTU [Member] | Collar Contracts With Short Puts for Year 2 [Member] | Short Put [Member]
Derivative [Line Items]
Derivative, Notional Amount, Price Per Unit	3.00
Gas contracts, price per MMBTU [Member] | Collar Contracts With Short Puts for Year 3 [Member]
Derivative [Line Items]
Derivative, Average Cap Price	5.36
Derivative, Average Floor Price	4.00
Gas contracts, price per MMBTU [Member] | Collar Contracts With Short Puts for Year 3 [Member] | Short Put [Member]
Derivative [Line Items]
Derivative, Notional Amount, Price Per Unit	3.00
Gas contracts, price per MMBTU [Member] | Basis Swap Contracts for Next Twelve Months [Member]
Derivative [Line Items]
Derivative, Swap Type, Average Fixed Price	(0.20)
Gas contracts, price per MMBTU [Member] | Basis Swap Contracts for Year 2 [Member]
Derivative [Line Items]
Derivative, Swap Type, Average Fixed Price	(0.18)
Gas contracts, price per MMBTU [Member] | Basis Swap Contracts for Year 3 [Member]
Derivative [Line Items]
Derivative, Swap Type, Average Fixed Price	0.00

[1] (a)Subsequent to December 31, 2013, the Company entered into additional basis swap contracts for 35,000 MMBTU per day of April through December 2014 production with a negative price differential of $0.27 per MMBTU between the relevant index price and the NYMEX price.