v2.3.0.15
Derivative Financial Instruments (Schedule of Open Commodity Derivative Positions) (Details) (USD $)
9 Months Ended
Sep. 30, 2011
Q4 2011 [Member] | Bbl [Member] | Open Oil Derivative Positions [Member] | Price Collars [Member]
 
Volume per day45,000
Weighted Average Floor Price75.00
Weighted Average Ceiling Price108.89
Q4 2011 [Member] | Bbl [Member] | Open Oil Derivative Positions [Member] | Call Options Sold [Member]
 
Volume per day19,500
Weighted Average Price95.00
Q4 2011 [Member] | Bbl [Member] | Open NGL Derivative Positions [Member] | NGL Basis Swap [Member]
 
Volume per day332
Weighted average differential between WTI and Natural Gasoline Dollars Per Barrel(9.75)
Q4 2011 [Member] | MMBtu [Member] | Open Natural Gas Derivative Positions [Member] | Price Swaps [Member]
 
Volume per day712,500
Weighted Average Price5.51
Q4 2011 [Member] | MMBtu [Member] | Open Natural Gas Derivative Positions [Member] | Price Collars [Member]
 
Volume per day287,935
Weighted Average Floor Price4.66
Weighted Average Ceiling Price5.07
Q4 2011 [Member] | MMBtu [Member] | Open Natural Gas Derivative Positions [Member] | Gas Basis Swap [Member]
 
Volume per day150,000
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 day22,000
Weighted Average Price107.17
Q1-Q4 2012 [Member] | Bbl [Member] | Open Oil Derivative Positions [Member] | Price Collars [Member]
 
Volume per day54,000
Weighted Average Floor Price85.74
Weighted Average Ceiling Price126.42
Q1-Q4 2012 [Member] | Bbl [Member] | Open Oil Derivative Positions [Member] | Call Options Sold [Member]
 
Volume per day19,500
Weighted Average Price95.00
Q1-Q4 2012 [Member] | Bbl [Member] | Open NGL Derivative Positions [Member] | NGL Basis Swap [Member]
 
Volume per day500
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 day325,000
Weighted Average Price5.09
Q1-Q4 2012 [Member] | MMBtu [Member] | Open Natural Gas Derivative Positions [Member] | Price Collars [Member]
 
Volume per day490,000
Weighted Average Floor Price4.75
Weighted Average Ceiling Price5.57
Q1-Q4 2012 [Member] | MMBtu [Member] | Open Natural Gas Derivative Positions [Member] | Call Options Sold [Member]
 
Volume per day487,500
Weighted Average Price6.00
Q1-Q4 2013 [Member] | Bbl [Member] | Open Oil Derivative Positions [Member] | Price Collars [Member]
 
Volume per day7,000
Weighted Average Floor Price90.00
Weighted Average Ceiling Price125.12
Q1-Q4 2013 [Member] | Bbl [Member] | Open NGL Derivative Positions [Member] | NGL Basis Swap [Member]
 
Volume per day500
Weighted average differential between WTI and Natural Gasoline Dollars Per Barrel(6.80)