Derivative Financial Instruments (Schedule Of Marketing And Basis Transfer Derivative Contracts) (Details)	3 Months Ended
	Jun. 30, 2012		Mar. 31, 2012
Average Daily Gas Production Associated with Marketing Derivatives (MMBtu) [Member]
Price Differential	0.15
Average Daily Gas Production Associated with Marketing Derivatives (MMBtu) [Member] | Basic Index Swaps [Member]
Index swap volume	13,297,000	[1]
Average Daily Gas Production Associated with Basis Transfer Derivatives (MMBtu) [Member]
NGI-So Cal Border Monthly price differential to NYMEX HH	0.13
IJ-HSC Price Differential To NYMEX HH	(0.06)
Average Daily Gas Production Associated with Basis Transfer Derivatives (MMBtu) [Member] | Basic Short Index Swaps [Member]
Index swap volume	1,648,000	[2]	5,000
NGI-So Cal Border Monthly price differential to NYMEX HH			0.12
Average Daily Gas Production Associated with Basis Transfer Derivatives (MMBtu) [Member] | Basic Long Index Swaps [Member]
Index swap volume	(1,648,000)	[2]	5,000
IJ-HSC Price Differential To NYMEX HH			0.05
May 2012 [Member] | Average Daily Gas Production Associated with Marketing Derivatives (MMBtu) [Member]
Index swap volume			30,000
Price per MMBtu			0.28
June Through October 2012 [Member] | Average Daily Gas Production Associated with Marketing Derivatives (MMBtu) [Member]
Index swap volume			40,000
Price per MMBtu			0.25

[1] Subsequent to March 31, 2012, the Company entered into additional marketing basis swap contracts for 30,000 MMBtus per day for May 2012 with a price of $0.28 and for 40,000 MMBtus per day for the period June through October 2012 with a price of $0.25 per MMBtu.

[2] Subsequent to March 31, 2012, the Company entered into (i) additional basis transfer short index swap contracts for 5,000 MMBtus per day for the period May through October 2012 with a price differential of $0.12 per MMBtu between NGI-So Cal Border Monthly and NYMEX HH and (ii) additional basis transfer long index swap contracts for 5,000 MMBtus per day for the period May through October 2012 with a price differential of $0.05 between IF-HSC and NYMEX HH.