Derivative Financial Instruments (Schedule Of Open Oil Derivative Positions And Open Gas Derivative Positions) (Details) (USD $)	6 Months Ended
	Jun. 30, 2011
Q3-Q4 2011 [Member] | Bbl [Member] | Open Oil Derivative Positions [Member] | Price Swaps [Member]
Volume per day
Weighted Average Price
Q3-Q4 2011 [Member] | Bbl [Member] | Open Oil Derivative Positions [Member] | Price Collars [Member]
Volume per day	45,000
Weighted Average Floor Price	75.00
Weighted Average Ceiling Price	108.89
Q3-Q4 2011 [Member] | Bbl [Member] | Open Oil Derivative Positions [Member] | Call Options Sold [Member]
Volume per day	19,500
Weighted Average Price	95.00
Q3-Q4 2011 [Member] | Bbl [Member] | Open NGL Derivative Positions [Member] | NGL Basis Swap [Member]
Volume per day	416
Weighted average differential between WTI and Natural Gasoline Dollars Per Barrel	(9.75)
Q3-Q4 2011 [Member] | MMBtu [Member] | Open Natural Gas Derivative Positions [Member] | Price Swaps [Member]
Volume per day	712,500
Weighted Average Price	5.51
Q3-Q4 2011 [Member] | MMBtu [Member] | Open Natural Gas Derivative Positions [Member] | Price Collars [Member]
Volume per day	215,000
Weighted Average Floor Price	4.75
Weighted Average Ceiling Price	5.17
Q3-Q4 2011 [Member] | MMBtu [Member] | Open Natural Gas Derivative Positions [Member] | Gas Basis Swap [Member]
Volume per day	150,000
Weighted Average Differential Between Henry Hub and Panhandle Eastern Pipeline Dollars Per Millions of British Thermal Units	(0.33)
Q1-Q4 2012 [Member] | Bbl [Member] | Open Oil Derivative Positions [Member] | Price Swaps [Member]
Volume per day	22,000
Weighted Average Price	107.17
Q1-Q4 2012 [Member] | Bbl [Member] | Open Oil Derivative Positions [Member] | Price Collars [Member]
Volume per day	54,000
Weighted Average Floor Price	85.74
Weighted Average Ceiling Price	126.42
Q1-Q4 2012 [Member] | Bbl [Member] | Open Oil Derivative Positions [Member] | Call Options Sold [Member]
Volume per day	19,500
Weighted Average Price	95.00
Q1-Q4 2012 [Member] | Bbl [Member] | Open NGL Derivative Positions [Member] | NGL Basis Swap [Member]
Volume per day	500
Weighted average differential between WTI and Natural Gasoline Dollars Per Barrel	(10.10)
Q1-Q4 2012 [Member] | MMBtu [Member] | Open Natural Gas Derivative Positions [Member] | Price Swaps [Member]
Volume per day	325,000
Weighted Average Price	5.09
Q1-Q4 2012 [Member] | MMBtu [Member] | Open Natural Gas Derivative Positions [Member] | Price Collars [Member]
Volume per day	490,000
Weighted Average Floor Price	4.75
Weighted Average Ceiling Price	5.57
Q1-Q4 2012 [Member] | MMBtu [Member] | Open Natural Gas Derivative Positions [Member] | Call Options Sold [Member]
Volume per day	487,500
Weighted Average Price	6.00
Q1-Q4 2013 [Member] | Bbl [Member] | Open Oil Derivative Positions [Member] | Price Swaps [Member]
Volume per day
Weighted Average Price
Q1-Q4 2013 [Member] | Bbl [Member] | Open Oil Derivative Positions [Member] | Price Collars [Member]
Volume per day	7,000
Weighted Average Floor Price	90.00
Weighted Average Ceiling Price	125.12
Q1-Q4 2013 [Member] | Bbl [Member] | Open Oil Derivative Positions [Member] | Call Options Sold [Member]
Volume per day
Weighted Average Price
Q1-Q4 2013 [Member] | Bbl [Member] | Open NGL Derivative Positions [Member] | NGL Basis Swap [Member]
Volume per day	500
Weighted average differential between WTI and Natural Gasoline Dollars Per Barrel	(6.80)