Derivative Financial Instruments (Schedule Of Oil Derivative Contracts Volume And Weighted Average Prices) (Details)	3 Months Ended
	Mar. 31, 2012 bbl
2012 - Swap Contracts [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Volume (Bbl)	3,000
Average Price per Bbl	79.32
2012 - Collar Contracts [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Volume (Bbl)	2,000
2012 - Collar Contracts [Member] | Ceiling [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Average Price per Bbl	127.00
2012 - Collar Contracts [Member] | Floor [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Average Price per Bbl	90.00
2012 - Collar Contracts With Short Puts [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Volume (Bbl)	48,301	[1]
2012 - Collar Contracts With Short Puts [Member] | Ceiling [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Average Price per Bbl	118.51
2012 - Collar Contracts With Short Puts [Member] | Floor [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Average Price per Bbl	83.72
2012 - Collar Contracts With Short Puts [Member] | Short Put [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Average Price per Bbl	67.97
2012 - Rollfactor Swap Contracts [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Volume (Bbl)	665
Average Price per Bbl	0.28	[2]
2012 - Basic Swap Contracts [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Volume (Bbl)	13,382
Average Price per Bbl	(1.15)	[3]
2013 - Swap Contracts [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Volume (Bbl)	3,000
Average Price per Bbl	81.02
2013 - Collar Contracts With Short Puts [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Volume (Bbl)	67,290	[1]
2013 - Collar Contracts With Short Puts [Member] | Ceiling [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Average Price per Bbl	120.61
2013 - Collar Contracts With Short Puts [Member] | Floor [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Average Price per Bbl	88.88
2013 - Collar Contracts With Short Puts [Member] | Short Put [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Average Price per Bbl	71.72
2013 - Rollfactor Swap Contracts [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Volume (Bbl)	6,000
Average Price per Bbl	0.43	[2]
2014 - Collar Contracts With Short Puts [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Volume (Bbl)	30,000	[1]
2014 - Collar Contracts With Short Puts [Member] | Ceiling [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Average Price per Bbl	123.39
2014 - Collar Contracts With Short Puts [Member] | Floor [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Average Price per Bbl	90.33
2014 - Collar Contracts With Short Puts [Member] | Short Put [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Average Price per Bbl	73.17
2014 - Subsequent Collar Contracts [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Volume (Bbl)	10,000
Average Price per Bbl	95.00
2014 - Subsequent Collar Contracts [Member] | Floor [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Average Price per Bbl	120.93
2014 - Subsequent Collar Contracts [Member] | Short Put [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Average Price per Bbl	80.00

[1] Subsequent to March 31, 2012, the Company entered into additional collar contracts with short puts for 10,000 Bbls per day of the Company's 2014 production with a ceiling price of $120.93 per Bbl, a floor price of $95.00 per Bbl and a short put price of $80.00 per Bbl.

[2] Weighted average spread between the NYMEX price for that delivery month and (i) the next month and (ii) the following month during the period when the delivery month is prompt.

[3] Basis differential between Midland WTI and Cushing WTI.