Derivative Financial Instruments Derivative Financial Instruments (Schedule of Gas Derivative Contracts Volume and Weighted Average Prices) (Details)	May 08, 2013 MMBTU		Mar. 31, 2013 MMBTU
Two Thousand Thirteen Collar Contracts With Short Puts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day			0
Two Thousand Thirteen Collar Contracts With Short Puts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Average Cap Price			0.00
Derivative, Average Floor Price			0.00
Two Thousand Thirteen Collar Contracts With Short Puts [Member] | Gas contracts, price per MMBTU [Member] | Short Put [Member]
Derivative [Line Items]
Nonmonetary Notional Amount of Price Risk Derivative Instruments Not Designated as Hedging Instruments			0.00
Two Thousand Sixteen Collar Contracts With Short Puts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day			20,000
Two Thousand Sixteen Collar Contracts With Short Puts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Average Cap Price			5.36
Derivative, Average Floor Price			4.00
Two Thousand Sixteen Collar Contracts With Short Puts [Member] | Gas contracts, price per MMBTU [Member] | Short Put [Member]
Derivative [Line Items]
Nonmonetary Notional Amount of Price Risk Derivative Instruments Not Designated as Hedging Instruments			3.00
Two Thousand Fifteen Collar Contracts With Short Puts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day	50,000	[1]	235,000	[1]
Two Thousand Fifteen Collar Contracts With Short Puts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Average Cap Price	5.03	[1]	5.09	[1]
Derivative, Average Floor Price	4.00	[1]	4.00	[1]
Two Thousand Fifteen Collar Contracts With Short Puts [Member] | Gas contracts, price per MMBTU [Member] | Short Put [Member]
Derivative [Line Items]
Nonmonetary Notional Amount of Price Risk Derivative Instruments Not Designated as Hedging Instruments	3.00	[1]	3.00	[1]
Two Thousand Fourteen Collar Contracts With Short Puts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day	50,000		65,000	[1]
Two Thousand Fourteen Collar Contracts With Short Puts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Average Cap Price	4.70		4.70	[1]
Derivative, Average Floor Price	4.00		4.00	[1]
Two Thousand Fourteen Collar Contracts With Short Puts [Member] | Gas contracts, price per MMBTU [Member] | Short Put [Member]
Derivative [Line Items]
Nonmonetary Notional Amount of Price Risk Derivative Instruments Not Designated as Hedging Instruments	3.00		3.00	[1]
Two Thousand Thirteen Collar Contracts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day	2,500		150,000	[1]
Two Thousand Thirteen Collar Contracts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Average Cap Price	4.50		6.25	[1]
Derivative, Average Floor Price	4.00		5.00	[1]
Two Thousand Fourteen Collar Contracts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day			0
Two Thousand Fourteen Collar Contracts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Average Cap Price			0.00
Derivative, Average Floor Price			0.00
Two Thousand Fifteen Collar Contracts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day			0
Two Thousand Fifteen Collar Contracts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Average Cap Price			0.00
Derivative, Average Floor Price			0.00
Two Thousand Sixteen Collar Contracts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day			0
Two Thousand Sixteen Collar Contracts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Average Cap Price			0.00
Derivative, Average Floor Price			0.00
Two Thousand Thirteen Swap Contracts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day			170,282
Two Thousand Thirteen Swap Contracts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Swap Type, Fixed Price			5.07
Two Thousand Fourteen Swap Contracts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day			175,000
Two Thousand Fourteen Swap Contracts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Swap Type, Fixed Price			4.02
2015 Swap Contracts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day			20,000
2015 Swap Contracts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Swap Type, Fixed Price			4.31
Two Thousand Sixteen Swap Contracts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day			0
Two Thousand Sixteen Swap Contracts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Swap Type, Fixed Price			0.00
Two Thousand And Thirteen Basis Swap Contracts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day			162,500
Two Thousand And Thirteen Basis Swap Contracts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Swap Type, Fixed Price			(0.22)
Two Thousand Fourteen Basis Swap Contracts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day	22,500		10,000	[1]
Two Thousand Fourteen Basis Swap Contracts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Swap Type, Fixed Price	(0.18)		(0.19)	[1]
Two Thousand Fifteen Basis Swap Contracts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day	7,500		0
Two Thousand Fifteen Basis Swap Contracts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Swap Type, Fixed Price	(0.13)		0.00
Two Thousand Sixteen Basis Swap Contracts [Member] | Gas contracts, in MMBTU [Member]
Derivative [Line Items]
Average Daily Gas Production Derivatives Volume per Day			0
Two Thousand Sixteen Basis Swap Contracts [Member] | Gas contracts, price per MMBTU [Member]
Derivative [Line Items]
Derivative, Swap Type, Fixed Price			0.00

[1] Subsequent to March 31, 2013, the Company entered into additional (i) collar contracts for 2,500 MMBTUs per day of the Company's June through December 2013 production with a ceiling price of $4.50 per MMBTU and a floor price of $4.00 per MMBTU, (ii) collar contracts with short puts for 50,000 MMBTUs per day of the Company's 2014 production with a ceiling price of $4.70 per MMBTU, a floor price of $4.00 per MMBTU and a short put price of $3.00 per MMBTU, (iii) collar contracts with short puts for 50,000 MMBTUs per day of the Company's 2015 production with a ceiling price of $5.03 per MMBTU, a floor price of $4.00 per MMBTU and a short put price of $3.00 per MMBTU, (iv) basis swap contracts for 22,500 MMBTU per day of the Company's 2014 production with a negative price differential of $0.18 per MMBTU between the relevant index price and the NYMEX price and (v) basis swap contracts for 7,500 MMBTU per day of the Company's 2015 production with a negative price differential of $0.13 per MMBTU between the relevant index price and the NYMEX price.