Derivative Instruments and Hedging Activities (Details 1)	Dec. 31, 2011
Year 2012 [Member] | Oil Contracts [Member] | Q1 [Member]
Derivative [Line Items]
Volume per day	53,250
Year 2012 [Member] | Oil Contracts [Member] | Q2 [Member]
Derivative [Line Items]
Volume per day	54,250
Year 2012 [Member] | Oil Contracts [Member] | Q3 [Member]
Derivative [Line Items]
Volume per day	54,250
Year 2012 [Member] | Oil Contracts [Member] | Q4 [Member]
Derivative [Line Items]
Volume per day	54,250
Year 2012 [Member] | Natural Gas Contracts [Member]
Derivative [Line Items]
Volume per day	20,000
Year 2012 [Member] | Collars [Member] | Oil Contracts [Member] | Q1 [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	70.00
Weighted average ceiling price	106.86
Volume per day	52,000
Derivative Price Range	70.00 – 139.60
Year 2012 [Member] | Collars [Member] | Oil Contracts [Member] | Q2 [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	70.00
Weighted average ceiling price	119.44
Volume per day	53,000
Derivative Price Range	70.00 – 137.50
Year 2012 [Member] | Collars [Member] | Oil Contracts [Member] | Q3 [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	80.00
Weighted average ceiling price	128.57
Volume per day	53,000
Derivative Price Range	80.00 – 140.65
Year 2012 [Member] | Collars [Member] | Oil Contracts [Member] | Q4 [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	80.00
Weighted average ceiling price	128.57
Volume per day	53,000
Derivative Price Range	80.00 – 140.65
Year 2012 [Member] | Collars [Member] | Natural Gas Contracts [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	0
Weighted average ceiling price	0
Volume per day	0
Derivative Price Range	-
Year 2012 [Member] | Swap [Member] | Oil Contracts [Member] | Q1 [Member]
Derivative [Line Items]
Weighted average swap price	81.04
Weighted average floor price	0
Weighted average ceiling price	0
Volume per day	625
Derivative Price Range	80.28 – 81.75
Year 2012 [Member] | Swap [Member] | Oil Contracts [Member] | Q2 [Member]
Derivative [Line Items]
Weighted average swap price	81.04
Weighted average floor price	0
Weighted average ceiling price	0
Volume per day	625
Derivative Price Range	80.28 – 81.75
Year 2012 [Member] | Swap [Member] | Oil Contracts [Member] | Q3 [Member]
Derivative [Line Items]
Weighted average swap price	81.04
Weighted average floor price	0
Weighted average ceiling price	0
Volume per day	625
Derivative Price Range	80.28 – 81.75
Year 2012 [Member] | Swap [Member] | Oil Contracts [Member] | Q4 [Member]
Derivative [Line Items]
Weighted average swap price	81.04
Weighted average floor price	0
Weighted average ceiling price	0
Volume per day	625
Derivative Price Range	80.28 – 81.75
Year 2012 [Member] | Swap [Member] | Natural Gas Contracts [Member]
Derivative [Line Items]
Weighted average swap price	6.53
Weighted average floor price	0
Weighted average ceiling price	0
Volume per day	20,000
Derivative Price Range	6.30 – 6.85
Year 2012 [Member] | Put [Member] | Oil Contracts [Member] | Q1 [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	65.00
Weighted average ceiling price	0
Volume per day	625
Derivative Price Range	65.00 – 65.00
Year 2012 [Member] | Put [Member] | Oil Contracts [Member] | Q2 [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	65.00
Weighted average ceiling price	0
Volume per day	625
Derivative Price Range	65.00 – 65.00
Year 2012 [Member] | Put [Member] | Oil Contracts [Member] | Q3 [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	65.00
Weighted average ceiling price	0
Volume per day	625
Derivative Price Range	65.00 – 65.00
Year 2012 [Member] | Put [Member] | Oil Contracts [Member] | Q4 [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	65.00
Weighted average ceiling price	0
Volume per day	625
Derivative Price Range	65.00 – 65.00
Year 2012 [Member] | Put [Member] | Natural Gas Contracts [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	0
Weighted average ceiling price	0
Volume per day	0
Derivative Price Range	-
Year 2013 [Member] | Oil Contracts [Member] | Q1 [Member]
Derivative [Line Items]
Volume per day	55,000
Year 2013 [Member] | Oil Contracts [Member] | Q2 [Member]
Derivative [Line Items]
Volume per day	42,000
Year 2013 [Member] | Collars [Member] | Oil Contracts [Member] | Q1 [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	70.00
Weighted average ceiling price	110.32
Volume per day	55,000
Derivative Price Range	70.00 – 117.00
Year 2013 [Member] | Collars [Member] | Oil Contracts [Member] | Q2 [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	75.00
Weighted average ceiling price	115.91
Volume per day	42,000
Derivative Price Range	75.00 – 118.00
Year 2013 [Member] | Swap [Member] | Oil Contracts [Member] | Q1 [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	0
Weighted average ceiling price	0
Volume per day	0
Derivative Price Range	-
Year 2013 [Member] | Swap [Member] | Oil Contracts [Member] | Q2 [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	0
Weighted average ceiling price	0
Volume per day	0
Derivative Price Range	-
Year 2013 [Member] | Put [Member] | Oil Contracts [Member] | Q1 [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	0
Weighted average ceiling price	0
Volume per day	0
Derivative Price Range	-
Year 2013 [Member] | Put [Member] | Oil Contracts [Member] | Q2 [Member]
Derivative [Line Items]
Weighted average swap price	0
Weighted average floor price	0
Weighted average ceiling price	0
Volume per day	0
Derivative Price Range	-